Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/exec.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * #!-checking implemented by tytso. |
| 9 | */ |
| 10 | /* |
| 11 | * Demand-loading implemented 01.12.91 - no need to read anything but |
| 12 | * the header into memory. The inode of the executable is put into |
| 13 | * "current->executable", and page faults do the actual loading. Clean. |
| 14 | * |
| 15 | * Once more I can proudly say that linux stood up to being changed: it |
| 16 | * was less than 2 hours work to get demand-loading completely implemented. |
| 17 | * |
| 18 | * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead, |
| 19 | * current->executable is only used by the procfs. This allows a dispatch |
| 20 | * table to check for several different types of binary formats. We keep |
| 21 | * trying until we recognize the file or we run out of supported binary |
| 22 | * formats. |
| 23 | */ |
| 24 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/slab.h> |
| 26 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 27 | #include <linux/fdtable.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 28 | #include <linux/mm.h> |
Davidlohr Bueso | 615d6e8 | 2014-04-07 15:37:25 -0700 | [diff] [blame] | 29 | #include <linux/vmacache.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <linux/stat.h> |
| 31 | #include <linux/fcntl.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 32 | #include <linux/swap.h> |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 33 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/init.h> |
Hugh Dickins | ca5b172 | 2008-07-28 15:46:18 -0700 | [diff] [blame] | 35 | #include <linux/pagemap.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 36 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <linux/highmem.h> |
| 38 | #include <linux/spinlock.h> |
| 39 | #include <linux/key.h> |
| 40 | #include <linux/personality.h> |
| 41 | #include <linux/binfmts.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <linux/utsname.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 43 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | #include <linux/module.h> |
| 45 | #include <linux/namei.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/mount.h> |
| 47 | #include <linux/security.h> |
| 48 | #include <linux/syscalls.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 49 | #include <linux/tsacct_kern.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 50 | #include <linux/cn_proc.h> |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 51 | #include <linux/audit.h> |
Roland McGrath | 6341c39 | 2008-07-25 19:45:44 -0700 | [diff] [blame] | 52 | #include <linux/tracehook.h> |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 53 | #include <linux/kmod.h> |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 54 | #include <linux/fsnotify.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 55 | #include <linux/fs_struct.h> |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 56 | #include <linux/pipe_fs_i.h> |
Ying Han | 3d5992d | 2010-10-26 14:21:23 -0700 | [diff] [blame] | 57 | #include <linux/oom.h> |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 58 | #include <linux/compat.h> |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 59 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
| 61 | #include <asm/uaccess.h> |
| 62 | #include <asm/mmu_context.h> |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 63 | #include <asm/tlb.h> |
KAMEZAWA Hiroyuki | 43d2b11 | 2012-01-10 15:08:09 -0800 | [diff] [blame] | 64 | |
| 65 | #include <trace/events/task.h> |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 66 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
David Smith | 4ff16c2 | 2012-02-07 10:11:05 -0600 | [diff] [blame] | 68 | #include <trace/events/sched.h> |
| 69 | |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 70 | int suid_dumpable = 0; |
| 71 | |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 72 | static LIST_HEAD(formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | static DEFINE_RWLOCK(binfmt_lock); |
| 74 | |
Al Viro | 8fc3dc5 | 2012-03-17 03:05:16 -0400 | [diff] [blame] | 75 | void __register_binfmt(struct linux_binfmt * fmt, int insert) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | { |
Al Viro | 8fc3dc5 | 2012-03-17 03:05:16 -0400 | [diff] [blame] | 77 | BUG_ON(!fmt); |
Oleg Nesterov | 92eaa56 | 2013-09-11 14:24:42 -0700 | [diff] [blame] | 78 | if (WARN_ON(!fmt->load_binary)) |
| 79 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | write_lock(&binfmt_lock); |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 81 | insert ? list_add(&fmt->lh, &formats) : |
| 82 | list_add_tail(&fmt->lh, &formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | } |
| 85 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 86 | EXPORT_SYMBOL(__register_binfmt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | |
Alexey Dobriyan | f6b450d | 2007-10-16 23:26:04 -0700 | [diff] [blame] | 88 | void unregister_binfmt(struct linux_binfmt * fmt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | write_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 91 | list_del(&fmt->lh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | EXPORT_SYMBOL(unregister_binfmt); |
| 96 | |
| 97 | static inline void put_binfmt(struct linux_binfmt * fmt) |
| 98 | { |
| 99 | module_put(fmt->module); |
| 100 | } |
| 101 | |
Eric W. Biederman | 90f8572 | 2015-06-29 14:42:03 -0500 | [diff] [blame] | 102 | bool path_noexec(const struct path *path) |
| 103 | { |
| 104 | return (path->mnt->mnt_flags & MNT_NOEXEC) || |
| 105 | (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC); |
| 106 | } |
| 107 | |
Josh Triplett | 69369a7 | 2014-04-03 14:48:27 -0700 | [diff] [blame] | 108 | #ifdef CONFIG_USELIB |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /* |
| 110 | * Note that a shared library must be both readable and executable due to |
| 111 | * security reasons. |
| 112 | * |
| 113 | * Also note that we take the address to load from from the file itself. |
| 114 | */ |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 115 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | { |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 117 | struct linux_binfmt *fmt; |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 118 | struct file *file; |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 119 | struct filename *tmp = getname(library); |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 120 | int error = PTR_ERR(tmp); |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 121 | static const struct open_flags uselib_flags = { |
| 122 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
Al Viro | 62fb4a1 | 2015-12-26 22:33:24 -0500 | [diff] [blame] | 123 | .acc_mode = MAY_READ | MAY_EXEC, |
Al Viro | f9652e1 | 2013-06-11 08:23:01 +0400 | [diff] [blame] | 124 | .intent = LOOKUP_OPEN, |
| 125 | .lookup_flags = LOOKUP_FOLLOW, |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 126 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 128 | if (IS_ERR(tmp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | goto out; |
| 130 | |
Al Viro | f9652e1 | 2013-06-11 08:23:01 +0400 | [diff] [blame] | 131 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 132 | putname(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | error = PTR_ERR(file); |
| 134 | if (IS_ERR(file)) |
| 135 | goto out; |
| 136 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 137 | error = -EINVAL; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 138 | if (!S_ISREG(file_inode(file)->i_mode)) |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 139 | goto exit; |
| 140 | |
| 141 | error = -EACCES; |
Eric W. Biederman | 90f8572 | 2015-06-29 14:42:03 -0500 | [diff] [blame] | 142 | if (path_noexec(&file->f_path)) |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 143 | goto exit; |
| 144 | |
Eric Paris | 2a12a9d | 2009-12-17 21:24:21 -0500 | [diff] [blame] | 145 | fsnotify_open(file); |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 146 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | error = -ENOEXEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 149 | read_lock(&binfmt_lock); |
| 150 | list_for_each_entry(fmt, &formats, lh) { |
| 151 | if (!fmt->load_shlib) |
| 152 | continue; |
| 153 | if (!try_module_get(fmt->module)) |
| 154 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | read_unlock(&binfmt_lock); |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 156 | error = fmt->load_shlib(file); |
| 157 | read_lock(&binfmt_lock); |
| 158 | put_binfmt(fmt); |
| 159 | if (error != -ENOEXEC) |
| 160 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | } |
Al Viro | 72c2d53 | 2013-09-22 16:27:52 -0400 | [diff] [blame] | 162 | read_unlock(&binfmt_lock); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 163 | exit: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | fput(file); |
| 165 | out: |
| 166 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
Josh Triplett | 69369a7 | 2014-04-03 14:48:27 -0700 | [diff] [blame] | 168 | #endif /* #ifdef CONFIG_USELIB */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 170 | #ifdef CONFIG_MMU |
Oleg Nesterov | ae6b585 | 2011-03-06 18:03:11 +0100 | [diff] [blame] | 171 | /* |
| 172 | * The nascent bprm->mm is not visible until exec_mmap() but it can |
| 173 | * use a lot of memory, account these pages in current->mm temporary |
| 174 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we |
| 175 | * change the counter back via acct_arg_size(0). |
| 176 | */ |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 177 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 178 | { |
| 179 | struct mm_struct *mm = current->mm; |
| 180 | long diff = (long)(pages - bprm->vma_pages); |
| 181 | |
| 182 | if (!mm || !diff) |
| 183 | return; |
| 184 | |
| 185 | bprm->vma_pages = pages; |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 186 | add_mm_counter(mm, MM_ANONPAGES, diff); |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 187 | } |
| 188 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 189 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 190 | int write) |
| 191 | { |
| 192 | struct page *page; |
| 193 | int ret; |
| 194 | |
| 195 | #ifdef CONFIG_STACK_GROWSUP |
| 196 | if (write) { |
Michal Hocko | d05f316 | 2011-05-24 17:11:44 -0700 | [diff] [blame] | 197 | ret = expand_downwards(bprm->vma, pos); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 198 | if (ret < 0) |
| 199 | return NULL; |
| 200 | } |
| 201 | #endif |
Dave Hansen | 1e98779 | 2016-02-12 13:01:54 -0800 | [diff] [blame] | 202 | /* |
| 203 | * We are doing an exec(). 'current' is the process |
| 204 | * doing the exec and bprm->mm is the new process's mm. |
| 205 | */ |
| 206 | ret = get_user_pages_remote(current, bprm->mm, pos, 1, write, |
| 207 | 1, &page, NULL); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 208 | if (ret <= 0) |
| 209 | return NULL; |
| 210 | |
| 211 | if (write) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 212 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 213 | struct rlimit *rlim; |
| 214 | |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 215 | acct_arg_size(bprm, size / PAGE_SIZE); |
| 216 | |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 217 | /* |
| 218 | * We've historically supported up to 32 pages (ARG_MAX) |
| 219 | * of argument strings even with small stacks |
| 220 | */ |
| 221 | if (size <= ARG_MAX) |
| 222 | return page; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 223 | |
| 224 | /* |
| 225 | * Limit to 1/4-th the stack size for the argv+env strings. |
| 226 | * This ensures that: |
| 227 | * - the remaining binfmt code will not run out of stack space, |
| 228 | * - the program will have a reasonable amount of stack left |
| 229 | * to work from. |
| 230 | */ |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 231 | rlim = current->signal->rlim; |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 232 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 233 | put_page(page); |
| 234 | return NULL; |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | return page; |
| 239 | } |
| 240 | |
| 241 | static void put_arg_page(struct page *page) |
| 242 | { |
| 243 | put_page(page); |
| 244 | } |
| 245 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 246 | static void free_arg_pages(struct linux_binprm *bprm) |
| 247 | { |
| 248 | } |
| 249 | |
| 250 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 251 | struct page *page) |
| 252 | { |
| 253 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); |
| 254 | } |
| 255 | |
| 256 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 257 | { |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 258 | int err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 259 | struct vm_area_struct *vma = NULL; |
| 260 | struct mm_struct *mm = bprm->mm; |
| 261 | |
| 262 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
| 263 | if (!vma) |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 264 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 265 | |
Michal Hocko | f268dfe | 2016-05-23 16:26:02 -0700 | [diff] [blame] | 266 | if (down_write_killable(&mm->mmap_sem)) { |
| 267 | err = -EINTR; |
| 268 | goto err_free; |
| 269 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 270 | vma->vm_mm = mm; |
| 271 | |
| 272 | /* |
| 273 | * Place the stack at the largest stack address the architecture |
| 274 | * supports. Later, we'll move this to an appropriate place. We don't |
| 275 | * use STACK_TOP because that can depend on attributes which aren't |
| 276 | * configured yet. |
| 277 | */ |
Michal Hocko | aacb3d1 | 2011-07-26 16:08:40 -0700 | [diff] [blame] | 278 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 279 | vma->vm_end = STACK_TOP_MAX; |
| 280 | vma->vm_start = vma->vm_end - PAGE_SIZE; |
Cyrill Gorcunov | d9104d1 | 2013-09-11 14:22:24 -0700 | [diff] [blame] | 281 | vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
Coly Li | 3ed75eb | 2007-10-18 23:39:15 -0700 | [diff] [blame] | 282 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 283 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
Tavis Ormandy | 462e635e | 2010-12-09 15:29:42 +0100 | [diff] [blame] | 284 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 285 | err = insert_vm_struct(mm, vma); |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 286 | if (err) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 287 | goto err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 288 | |
| 289 | mm->stack_vm = mm->total_vm = 1; |
Dave Hansen | fe3d197 | 2014-11-14 07:18:29 -0800 | [diff] [blame] | 290 | arch_bprm_mm_init(mm, vma); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 291 | up_write(&mm->mmap_sem); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 292 | bprm->p = vma->vm_end - sizeof(void *); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 293 | return 0; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 294 | err: |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 295 | up_write(&mm->mmap_sem); |
Michal Hocko | f268dfe | 2016-05-23 16:26:02 -0700 | [diff] [blame] | 296 | err_free: |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 297 | bprm->vma = NULL; |
| 298 | kmem_cache_free(vm_area_cachep, vma); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 299 | return err; |
| 300 | } |
| 301 | |
| 302 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 303 | { |
| 304 | return len <= MAX_ARG_STRLEN; |
| 305 | } |
| 306 | |
| 307 | #else |
| 308 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 309 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 310 | { |
| 311 | } |
| 312 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 313 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 314 | int write) |
| 315 | { |
| 316 | struct page *page; |
| 317 | |
| 318 | page = bprm->page[pos / PAGE_SIZE]; |
| 319 | if (!page && write) { |
| 320 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); |
| 321 | if (!page) |
| 322 | return NULL; |
| 323 | bprm->page[pos / PAGE_SIZE] = page; |
| 324 | } |
| 325 | |
| 326 | return page; |
| 327 | } |
| 328 | |
| 329 | static void put_arg_page(struct page *page) |
| 330 | { |
| 331 | } |
| 332 | |
| 333 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 334 | { |
| 335 | if (bprm->page[i]) { |
| 336 | __free_page(bprm->page[i]); |
| 337 | bprm->page[i] = NULL; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | static void free_arg_pages(struct linux_binprm *bprm) |
| 342 | { |
| 343 | int i; |
| 344 | |
| 345 | for (i = 0; i < MAX_ARG_PAGES; i++) |
| 346 | free_arg_page(bprm, i); |
| 347 | } |
| 348 | |
| 349 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 350 | struct page *page) |
| 351 | { |
| 352 | } |
| 353 | |
| 354 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 355 | { |
| 356 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 361 | { |
| 362 | return len <= bprm->p; |
| 363 | } |
| 364 | |
| 365 | #endif /* CONFIG_MMU */ |
| 366 | |
| 367 | /* |
| 368 | * Create a new mm_struct and populate it with a temporary stack |
| 369 | * vm_area_struct. We don't have enough context at this point to set the stack |
| 370 | * flags, permissions, and offset, so we use temporary values. We'll update |
| 371 | * them later in setup_arg_pages(). |
| 372 | */ |
Yuanhan Liu | 9cc64ce | 2013-02-20 13:16:01 +1100 | [diff] [blame] | 373 | static int bprm_mm_init(struct linux_binprm *bprm) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 374 | { |
| 375 | int err; |
| 376 | struct mm_struct *mm = NULL; |
| 377 | |
| 378 | bprm->mm = mm = mm_alloc(); |
| 379 | err = -ENOMEM; |
| 380 | if (!mm) |
| 381 | goto err; |
| 382 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 383 | err = __bprm_mm_init(bprm); |
| 384 | if (err) |
| 385 | goto err; |
| 386 | |
| 387 | return 0; |
| 388 | |
| 389 | err: |
| 390 | if (mm) { |
| 391 | bprm->mm = NULL; |
| 392 | mmdrop(mm); |
| 393 | } |
| 394 | |
| 395 | return err; |
| 396 | } |
| 397 | |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 398 | struct user_arg_ptr { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 399 | #ifdef CONFIG_COMPAT |
| 400 | bool is_compat; |
| 401 | #endif |
| 402 | union { |
| 403 | const char __user *const __user *native; |
| 404 | #ifdef CONFIG_COMPAT |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 405 | const compat_uptr_t __user *compat; |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 406 | #endif |
| 407 | } ptr; |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 408 | }; |
| 409 | |
| 410 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 411 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 412 | const char __user *native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 413 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 414 | #ifdef CONFIG_COMPAT |
| 415 | if (unlikely(argv.is_compat)) { |
| 416 | compat_uptr_t compat; |
| 417 | |
| 418 | if (get_user(compat, argv.ptr.compat + nr)) |
| 419 | return ERR_PTR(-EFAULT); |
| 420 | |
| 421 | return compat_ptr(compat); |
| 422 | } |
| 423 | #endif |
| 424 | |
| 425 | if (get_user(native, argv.ptr.native + nr)) |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 426 | return ERR_PTR(-EFAULT); |
| 427 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 428 | return native; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 429 | } |
| 430 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | /* |
| 432 | * count() counts the number of strings in array ARGV. |
| 433 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 434 | static int count(struct user_arg_ptr argv, int max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | { |
| 436 | int i = 0; |
| 437 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 438 | if (argv.ptr.native != NULL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | for (;;) { |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 440 | const char __user *p = get_user_arg_ptr(argv, i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | if (!p) |
| 443 | break; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 444 | |
| 445 | if (IS_ERR(p)) |
| 446 | return -EFAULT; |
| 447 | |
Xi Wang | 6d92d4f | 2013-01-11 14:31:48 -0800 | [diff] [blame] | 448 | if (i >= max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | return -E2BIG; |
Xi Wang | 6d92d4f | 2013-01-11 14:31:48 -0800 | [diff] [blame] | 450 | ++i; |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 451 | |
| 452 | if (fatal_signal_pending(current)) |
| 453 | return -ERESTARTNOHAND; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | cond_resched(); |
| 455 | } |
| 456 | } |
| 457 | return i; |
| 458 | } |
| 459 | |
| 460 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 461 | * 'copy_strings()' copies argument/environment strings from the old |
| 462 | * processes's memory to the new process's stack. The call to get_user_pages() |
| 463 | * ensures the destination page is created and not swapped out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 465 | static int copy_strings(int argc, struct user_arg_ptr argv, |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 466 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | { |
| 468 | struct page *kmapped_page = NULL; |
| 469 | char *kaddr = NULL; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 470 | unsigned long kpos = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | int ret; |
| 472 | |
| 473 | while (argc-- > 0) { |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 474 | const char __user *str; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | int len; |
| 476 | unsigned long pos; |
| 477 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 478 | ret = -EFAULT; |
| 479 | str = get_user_arg_ptr(argv, argc); |
| 480 | if (IS_ERR(str)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 483 | len = strnlen_user(str, MAX_ARG_STRLEN); |
| 484 | if (!len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | goto out; |
Oleg Nesterov | 1d1dbf8 | 2011-03-06 18:02:21 +0100 | [diff] [blame] | 486 | |
| 487 | ret = -E2BIG; |
| 488 | if (!valid_arg_len(bprm, len)) |
| 489 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 491 | /* We're going to work our way backwords. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | pos = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 493 | str += len; |
| 494 | bprm->p -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | |
| 496 | while (len > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | int offset, bytes_to_copy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
Roland McGrath | 9aea5a6 | 2010-09-07 19:37:06 -0700 | [diff] [blame] | 499 | if (fatal_signal_pending(current)) { |
| 500 | ret = -ERESTARTNOHAND; |
| 501 | goto out; |
| 502 | } |
Roland McGrath | 7993bc1 | 2010-09-07 19:36:28 -0700 | [diff] [blame] | 503 | cond_resched(); |
| 504 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | offset = pos % PAGE_SIZE; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 506 | if (offset == 0) |
| 507 | offset = PAGE_SIZE; |
| 508 | |
| 509 | bytes_to_copy = offset; |
| 510 | if (bytes_to_copy > len) |
| 511 | bytes_to_copy = len; |
| 512 | |
| 513 | offset -= bytes_to_copy; |
| 514 | pos -= bytes_to_copy; |
| 515 | str -= bytes_to_copy; |
| 516 | len -= bytes_to_copy; |
| 517 | |
| 518 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { |
| 519 | struct page *page; |
| 520 | |
| 521 | page = get_arg_page(bprm, pos, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | if (!page) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 523 | ret = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | goto out; |
| 525 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 527 | if (kmapped_page) { |
| 528 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 530 | put_arg_page(kmapped_page); |
| 531 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | kmapped_page = page; |
| 533 | kaddr = kmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 534 | kpos = pos & PAGE_MASK; |
| 535 | flush_arg_page(bprm, kpos, kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 537 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | ret = -EFAULT; |
| 539 | goto out; |
| 540 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | } |
| 542 | } |
| 543 | ret = 0; |
| 544 | out: |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 545 | if (kmapped_page) { |
| 546 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 548 | put_arg_page(kmapped_page); |
| 549 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | return ret; |
| 551 | } |
| 552 | |
| 553 | /* |
| 554 | * Like copy_strings, but get argv and its values from kernel memory. |
| 555 | */ |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 556 | int copy_strings_kernel(int argc, const char *const *__argv, |
David Howells | d762746 | 2010-08-17 23:52:56 +0100 | [diff] [blame] | 557 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | { |
| 559 | int r; |
| 560 | mm_segment_t oldfs = get_fs(); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 561 | struct user_arg_ptr argv = { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 562 | .ptr.native = (const char __user *const __user *)__argv, |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 563 | }; |
| 564 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | set_fs(KERNEL_DS); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 566 | r = copy_strings(argc, argv, bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | set_fs(oldfs); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 568 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | return r; |
| 570 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | EXPORT_SYMBOL(copy_strings_kernel); |
| 572 | |
| 573 | #ifdef CONFIG_MMU |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 574 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 576 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
| 577 | * the binfmt code determines where the new stack should reside, we shift it to |
| 578 | * its final location. The process proceeds as follows: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | * |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 580 | * 1) Use shift to calculate the new vma endpoints. |
| 581 | * 2) Extend vma to cover both the old and new ranges. This ensures the |
| 582 | * arguments passed to subsequent functions are consistent. |
| 583 | * 3) Move vma's page tables to the new range. |
| 584 | * 4) Free up any cleared pgd range. |
| 585 | * 5) Shrink the vma to cover only the new range. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 587 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | { |
| 589 | struct mm_struct *mm = vma->vm_mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 590 | unsigned long old_start = vma->vm_start; |
| 591 | unsigned long old_end = vma->vm_end; |
| 592 | unsigned long length = old_end - old_start; |
| 593 | unsigned long new_start = old_start - shift; |
| 594 | unsigned long new_end = old_end - shift; |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 595 | struct mmu_gather tlb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 597 | BUG_ON(new_start > new_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 599 | /* |
| 600 | * ensure there are no vmas between where we want to go |
| 601 | * and where we are |
| 602 | */ |
| 603 | if (vma != find_vma(mm, new_start)) |
| 604 | return -EFAULT; |
| 605 | |
| 606 | /* |
| 607 | * cover the whole range: [new_start, old_end) |
| 608 | */ |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 609 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
| 610 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 611 | |
| 612 | /* |
| 613 | * move the page tables downwards, on failure we rely on |
| 614 | * process cleanup to remove whatever mess we made. |
| 615 | */ |
| 616 | if (length != move_page_tables(vma, old_start, |
Michel Lespinasse | 38a7601 | 2012-10-08 16:31:50 -0700 | [diff] [blame] | 617 | vma, new_start, length, false)) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 618 | return -ENOMEM; |
| 619 | |
| 620 | lru_add_drain(); |
Linus Torvalds | 2b04725 | 2013-08-15 11:42:25 -0700 | [diff] [blame] | 621 | tlb_gather_mmu(&tlb, mm, old_start, old_end); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 622 | if (new_end > old_start) { |
| 623 | /* |
| 624 | * when the old and new regions overlap clear from new_end. |
| 625 | */ |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 626 | free_pgd_range(&tlb, new_end, old_end, new_end, |
Hugh Dickins | 6ee8630 | 2013-04-29 15:07:44 -0700 | [diff] [blame] | 627 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 628 | } else { |
| 629 | /* |
| 630 | * otherwise, clean from old_start; this is done to not touch |
| 631 | * the address space in [new_end, old_start) some architectures |
| 632 | * have constraints on va-space that make this illegal (IA64) - |
| 633 | * for the others its just a little faster. |
| 634 | */ |
Peter Zijlstra | d16dfc5 | 2011-05-24 17:11:45 -0700 | [diff] [blame] | 635 | free_pgd_range(&tlb, old_start, old_end, new_end, |
Hugh Dickins | 6ee8630 | 2013-04-29 15:07:44 -0700 | [diff] [blame] | 636 | vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 637 | } |
Linus Torvalds | 2b04725 | 2013-08-15 11:42:25 -0700 | [diff] [blame] | 638 | tlb_finish_mmu(&tlb, old_start, old_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 640 | /* |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 641 | * Shrink the vma to just the new range. Always succeeds. |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 642 | */ |
| 643 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); |
| 644 | |
| 645 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | } |
| 647 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 648 | /* |
| 649 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, |
| 650 | * the stack is optionally relocated, and some extra space is added. |
| 651 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | int setup_arg_pages(struct linux_binprm *bprm, |
| 653 | unsigned long stack_top, |
| 654 | int executable_stack) |
| 655 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 656 | unsigned long ret; |
| 657 | unsigned long stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | struct mm_struct *mm = current->mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 659 | struct vm_area_struct *vma = bprm->vma; |
| 660 | struct vm_area_struct *prev = NULL; |
| 661 | unsigned long vm_flags; |
| 662 | unsigned long stack_base; |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 663 | unsigned long stack_size; |
| 664 | unsigned long stack_expand; |
| 665 | unsigned long rlim_stack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | |
| 667 | #ifdef CONFIG_STACK_GROWSUP |
James Hogan | d71f290 | 2014-05-13 23:58:24 +0100 | [diff] [blame] | 668 | /* Limit stack size */ |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 669 | stack_base = rlimit_max(RLIMIT_STACK); |
James Hogan | d71f290 | 2014-05-13 23:58:24 +0100 | [diff] [blame] | 670 | if (stack_base > STACK_SIZE_MAX) |
| 671 | stack_base = STACK_SIZE_MAX; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | |
Helge Deller | d045c77 | 2015-05-11 22:01:27 +0200 | [diff] [blame] | 673 | /* Add space for stack randomization. */ |
| 674 | stack_base += (STACK_RND_MASK << PAGE_SHIFT); |
| 675 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 676 | /* Make sure we didn't let the argument array grow too large. */ |
| 677 | if (vma->vm_end - vma->vm_start > stack_base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | return -ENOMEM; |
| 679 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 680 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
| 681 | |
| 682 | stack_shift = vma->vm_start - stack_base; |
| 683 | mm->arg_start = bprm->p - stack_shift; |
| 684 | bprm->p = vma->vm_end - stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | #else |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 686 | stack_top = arch_align_stack(stack_top); |
| 687 | stack_top = PAGE_ALIGN(stack_top); |
Roland McGrath | 1b52818 | 2010-09-07 19:35:49 -0700 | [diff] [blame] | 688 | |
| 689 | if (unlikely(stack_top < mmap_min_addr) || |
| 690 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) |
| 691 | return -ENOMEM; |
| 692 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 693 | stack_shift = vma->vm_end - stack_top; |
| 694 | |
| 695 | bprm->p -= stack_shift; |
| 696 | mm->arg_start = bprm->p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | #endif |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 698 | |
| 699 | if (bprm->loader) |
| 700 | bprm->loader -= stack_shift; |
| 701 | bprm->exec -= stack_shift; |
| 702 | |
Michal Hocko | f268dfe | 2016-05-23 16:26:02 -0700 | [diff] [blame] | 703 | if (down_write_killable(&mm->mmap_sem)) |
| 704 | return -EINTR; |
| 705 | |
Hugh Dickins | 96a8e13 | 2008-07-10 21:19:20 +0100 | [diff] [blame] | 706 | vm_flags = VM_STACK_FLAGS; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 707 | |
| 708 | /* |
| 709 | * Adjust stack execute permissions; explicitly enable for |
| 710 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone |
| 711 | * (arch default) otherwise. |
| 712 | */ |
| 713 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) |
| 714 | vm_flags |= VM_EXEC; |
| 715 | else if (executable_stack == EXSTACK_DISABLE_X) |
| 716 | vm_flags &= ~VM_EXEC; |
| 717 | vm_flags |= mm->def_flags; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 718 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 719 | |
| 720 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, |
| 721 | vm_flags); |
| 722 | if (ret) |
| 723 | goto out_unlock; |
| 724 | BUG_ON(prev != vma); |
| 725 | |
| 726 | /* Move stack pages down in memory. */ |
| 727 | if (stack_shift) { |
| 728 | ret = shift_arg_pages(vma, stack_shift); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 729 | if (ret) |
| 730 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | } |
| 732 | |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 733 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
| 734 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; |
| 735 | |
Michael Neuling | 5ef097d | 2010-03-05 13:42:57 -0800 | [diff] [blame] | 736 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 737 | stack_size = vma->vm_end - vma->vm_start; |
| 738 | /* |
| 739 | * Align this down to a page boundary as expand_stack |
| 740 | * will align it up. |
| 741 | */ |
| 742 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 743 | #ifdef CONFIG_STACK_GROWSUP |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 744 | if (stack_size + stack_expand > rlim_stack) |
| 745 | stack_base = vma->vm_start + rlim_stack; |
| 746 | else |
| 747 | stack_base = vma->vm_end + stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 748 | #else |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 749 | if (stack_size + stack_expand > rlim_stack) |
| 750 | stack_base = vma->vm_end - rlim_stack; |
| 751 | else |
| 752 | stack_base = vma->vm_start - stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 753 | #endif |
Eric B Munson | 3af9e85 | 2010-05-18 15:30:49 +0100 | [diff] [blame] | 754 | current->mm->start_stack = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 755 | ret = expand_stack(vma, stack_base); |
| 756 | if (ret) |
| 757 | ret = -EFAULT; |
| 758 | |
| 759 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | up_write(&mm->mmap_sem); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 761 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | EXPORT_SYMBOL(setup_arg_pages); |
| 764 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | #endif /* CONFIG_MMU */ |
| 766 | |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 767 | static struct file *do_open_execat(int fd, struct filename *name, int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | struct file *file; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 770 | int err; |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 771 | struct open_flags open_exec_flags = { |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 772 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, |
Al Viro | 62fb4a1 | 2015-12-26 22:33:24 -0500 | [diff] [blame] | 773 | .acc_mode = MAY_EXEC, |
Al Viro | f9652e1 | 2013-06-11 08:23:01 +0400 | [diff] [blame] | 774 | .intent = LOOKUP_OPEN, |
| 775 | .lookup_flags = LOOKUP_FOLLOW, |
Al Viro | 47c805d | 2011-02-23 17:44:09 -0500 | [diff] [blame] | 776 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 778 | if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
| 779 | return ERR_PTR(-EINVAL); |
| 780 | if (flags & AT_SYMLINK_NOFOLLOW) |
| 781 | open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW; |
| 782 | if (flags & AT_EMPTY_PATH) |
| 783 | open_exec_flags.lookup_flags |= LOOKUP_EMPTY; |
| 784 | |
| 785 | file = do_filp_open(fd, name, &open_exec_flags); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 786 | if (IS_ERR(file)) |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 787 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 789 | err = -EACCES; |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 790 | if (!S_ISREG(file_inode(file)->i_mode)) |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 791 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 792 | |
Eric W. Biederman | 90f8572 | 2015-06-29 14:42:03 -0500 | [diff] [blame] | 793 | if (path_noexec(&file->f_path)) |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 794 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 795 | |
| 796 | err = deny_write_access(file); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 797 | if (err) |
| 798 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 800 | if (name->name[0] != '\0') |
| 801 | fsnotify_open(file); |
| 802 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 803 | out: |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 804 | return file; |
| 805 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 806 | exit: |
| 807 | fput(file); |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 808 | return ERR_PTR(err); |
| 809 | } |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 810 | |
| 811 | struct file *open_exec(const char *name) |
| 812 | { |
Paul Moore | 5168910 | 2015-01-22 00:00:03 -0500 | [diff] [blame] | 813 | struct filename *filename = getname_kernel(name); |
| 814 | struct file *f = ERR_CAST(filename); |
| 815 | |
| 816 | if (!IS_ERR(filename)) { |
| 817 | f = do_open_execat(AT_FDCWD, filename, 0); |
| 818 | putname(filename); |
| 819 | } |
| 820 | return f; |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 821 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | EXPORT_SYMBOL(open_exec); |
| 823 | |
Mimi Zohar | 6777d77 | 2009-08-21 14:32:48 -0400 | [diff] [blame] | 824 | int kernel_read(struct file *file, loff_t offset, |
| 825 | char *addr, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | { |
| 827 | mm_segment_t old_fs; |
| 828 | loff_t pos = offset; |
| 829 | int result; |
| 830 | |
| 831 | old_fs = get_fs(); |
| 832 | set_fs(get_ds()); |
| 833 | /* The cast to a user pointer is valid due to the set_fs() */ |
| 834 | result = vfs_read(file, (void __user *)addr, count, &pos); |
| 835 | set_fs(old_fs); |
| 836 | return result; |
| 837 | } |
| 838 | |
| 839 | EXPORT_SYMBOL(kernel_read); |
| 840 | |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 841 | int kernel_read_file(struct file *file, void **buf, loff_t *size, |
Mimi Zohar | bc8ca5b | 2016-01-24 10:07:32 -0500 | [diff] [blame] | 842 | loff_t max_size, enum kernel_read_file_id id) |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 843 | { |
| 844 | loff_t i_size, pos; |
| 845 | ssize_t bytes = 0; |
| 846 | int ret; |
| 847 | |
| 848 | if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) |
| 849 | return -EINVAL; |
| 850 | |
Mimi Zohar | 39eeb4f | 2016-01-30 22:23:26 -0500 | [diff] [blame] | 851 | ret = security_kernel_read_file(file, id); |
| 852 | if (ret) |
| 853 | return ret; |
| 854 | |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 855 | ret = deny_write_access(file); |
| 856 | if (ret) |
| 857 | return ret; |
| 858 | |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 859 | i_size = i_size_read(file_inode(file)); |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 860 | if (max_size > 0 && i_size > max_size) { |
| 861 | ret = -EFBIG; |
| 862 | goto out; |
| 863 | } |
| 864 | if (i_size <= 0) { |
| 865 | ret = -EINVAL; |
| 866 | goto out; |
| 867 | } |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 868 | |
| 869 | *buf = vmalloc(i_size); |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 870 | if (!*buf) { |
| 871 | ret = -ENOMEM; |
| 872 | goto out; |
| 873 | } |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 874 | |
| 875 | pos = 0; |
| 876 | while (pos < i_size) { |
| 877 | bytes = kernel_read(file, pos, (char *)(*buf) + pos, |
| 878 | i_size - pos); |
| 879 | if (bytes < 0) { |
| 880 | ret = bytes; |
| 881 | goto out; |
| 882 | } |
| 883 | |
| 884 | if (bytes == 0) |
| 885 | break; |
| 886 | pos += bytes; |
| 887 | } |
| 888 | |
| 889 | if (pos != i_size) { |
| 890 | ret = -EIO; |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 891 | goto out_free; |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 892 | } |
| 893 | |
Mimi Zohar | bc8ca5b | 2016-01-24 10:07:32 -0500 | [diff] [blame] | 894 | ret = security_kernel_post_read_file(file, *buf, i_size, id); |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 895 | if (!ret) |
| 896 | *size = pos; |
| 897 | |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 898 | out_free: |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 899 | if (ret < 0) { |
| 900 | vfree(*buf); |
| 901 | *buf = NULL; |
| 902 | } |
Dmitry Kasatkin | 39d637a | 2014-10-26 12:42:07 +0200 | [diff] [blame] | 903 | |
| 904 | out: |
| 905 | allow_write_access(file); |
Mimi Zohar | b44a7df | 2015-12-28 16:02:29 -0500 | [diff] [blame] | 906 | return ret; |
| 907 | } |
| 908 | EXPORT_SYMBOL_GPL(kernel_read_file); |
| 909 | |
Mimi Zohar | 09596b9 | 2015-11-19 12:39:22 -0500 | [diff] [blame] | 910 | int kernel_read_file_from_path(char *path, void **buf, loff_t *size, |
| 911 | loff_t max_size, enum kernel_read_file_id id) |
| 912 | { |
| 913 | struct file *file; |
| 914 | int ret; |
| 915 | |
| 916 | if (!path || !*path) |
| 917 | return -EINVAL; |
| 918 | |
| 919 | file = filp_open(path, O_RDONLY, 0); |
| 920 | if (IS_ERR(file)) |
| 921 | return PTR_ERR(file); |
| 922 | |
| 923 | ret = kernel_read_file(file, buf, size, max_size, id); |
| 924 | fput(file); |
| 925 | return ret; |
| 926 | } |
| 927 | EXPORT_SYMBOL_GPL(kernel_read_file_from_path); |
| 928 | |
Mimi Zohar | b844f0e | 2016-02-01 08:36:21 -0500 | [diff] [blame] | 929 | int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, |
| 930 | enum kernel_read_file_id id) |
| 931 | { |
| 932 | struct fd f = fdget(fd); |
| 933 | int ret = -EBADF; |
| 934 | |
| 935 | if (!f.file) |
| 936 | goto out; |
| 937 | |
| 938 | ret = kernel_read_file(f.file, buf, size, max_size, id); |
| 939 | out: |
| 940 | fdput(f); |
| 941 | return ret; |
| 942 | } |
| 943 | EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); |
| 944 | |
Al Viro | 3dc20cb | 2013-04-13 20:31:37 -0400 | [diff] [blame] | 945 | ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) |
| 946 | { |
Al Viro | ec69557 | 2014-02-04 19:08:21 -0500 | [diff] [blame] | 947 | ssize_t res = vfs_read(file, (void __user *)addr, len, &pos); |
Al Viro | 3dc20cb | 2013-04-13 20:31:37 -0400 | [diff] [blame] | 948 | if (res > 0) |
| 949 | flush_icache_range(addr, addr + len); |
| 950 | return res; |
| 951 | } |
| 952 | EXPORT_SYMBOL(read_code); |
| 953 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | static int exec_mmap(struct mm_struct *mm) |
| 955 | { |
| 956 | struct task_struct *tsk; |
Davidlohr Bueso | 615d6e8 | 2014-04-07 15:37:25 -0700 | [diff] [blame] | 957 | struct mm_struct *old_mm, *active_mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | |
| 959 | /* Notify parent that we're no longer interested in the old VM */ |
| 960 | tsk = current; |
| 961 | old_mm = current->mm; |
| 962 | mm_release(tsk, old_mm); |
| 963 | |
| 964 | if (old_mm) { |
Konstantin Khlebnikov | 4fe7efd | 2012-06-20 12:53:01 -0700 | [diff] [blame] | 965 | sync_mm_rss(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | /* |
| 967 | * Make sure that if there is a core dump in progress |
| 968 | * for the old mm, we get out and die instead of going |
| 969 | * through with the exec. We must hold mmap_sem around |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 970 | * checking core_state and changing tsk->mm. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | */ |
| 972 | down_read(&old_mm->mmap_sem); |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 973 | if (unlikely(old_mm->core_state)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | up_read(&old_mm->mmap_sem); |
| 975 | return -EINTR; |
| 976 | } |
| 977 | } |
| 978 | task_lock(tsk); |
| 979 | active_mm = tsk->active_mm; |
| 980 | tsk->mm = mm; |
| 981 | tsk->active_mm = mm; |
| 982 | activate_mm(active_mm, mm); |
Davidlohr Bueso | 615d6e8 | 2014-04-07 15:37:25 -0700 | [diff] [blame] | 983 | tsk->mm->vmacache_seqnum = 0; |
| 984 | vmacache_flush(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 985 | task_unlock(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | if (old_mm) { |
| 987 | up_read(&old_mm->mmap_sem); |
Eric Sesterhenn | 7dddb12 | 2006-04-01 01:13:38 +0200 | [diff] [blame] | 988 | BUG_ON(active_mm != old_mm); |
Oleg Nesterov | 701085b | 2012-03-19 17:04:01 +0100 | [diff] [blame] | 989 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
Balbir Singh | 31a78f2 | 2008-09-28 23:09:31 +0100 | [diff] [blame] | 990 | mm_update_next_owner(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | mmput(old_mm); |
| 992 | return 0; |
| 993 | } |
| 994 | mmdrop(active_mm); |
| 995 | return 0; |
| 996 | } |
| 997 | |
| 998 | /* |
| 999 | * This function makes sure the current process has its own signal table, |
| 1000 | * so that flush_signal_handlers can later reset the handlers without |
| 1001 | * disturbing other processes. (Other processes might share the signal |
| 1002 | * table via the CLONE_SIGHAND option to clone().) |
| 1003 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1004 | static int de_thread(struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | { |
| 1006 | struct signal_struct *sig = tsk->signal; |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1007 | struct sighand_struct *oldsighand = tsk->sighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | spinlock_t *lock = &oldsighand->siglock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1010 | if (thread_group_empty(tsk)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1011 | goto no_thread_group; |
| 1012 | |
| 1013 | /* |
| 1014 | * Kill all other threads in the thread group. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1015 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | spin_lock_irq(lock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 1017 | if (signal_group_exit(sig)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | /* |
| 1019 | * Another group action in progress, just |
| 1020 | * return so that the signal is processed. |
| 1021 | */ |
| 1022 | spin_unlock_irq(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | return -EAGAIN; |
| 1024 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | |
Oleg Nesterov | d344193 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 1026 | sig->group_exit_task = tsk; |
| 1027 | sig->notify_count = zap_other_threads(tsk); |
| 1028 | if (!thread_group_leader(tsk)) |
| 1029 | sig->notify_count--; |
| 1030 | |
| 1031 | while (sig->notify_count) { |
Oleg Nesterov | d5bbd43 | 2012-10-08 19:13:01 +0200 | [diff] [blame] | 1032 | __set_current_state(TASK_KILLABLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | spin_unlock_irq(lock); |
| 1034 | schedule(); |
Oleg Nesterov | d5bbd43 | 2012-10-08 19:13:01 +0200 | [diff] [blame] | 1035 | if (unlikely(__fatal_signal_pending(tsk))) |
| 1036 | goto killed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | spin_lock_irq(lock); |
| 1038 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | spin_unlock_irq(lock); |
| 1040 | |
| 1041 | /* |
| 1042 | * At this point all other threads have exited, all we have to |
| 1043 | * do is to wait for the thread group leader to become inactive, |
| 1044 | * and to assume its PID: |
| 1045 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1046 | if (!thread_group_leader(tsk)) { |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 1047 | struct task_struct *leader = tsk->group_leader; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1048 | |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1049 | for (;;) { |
Oleg Nesterov | e56fb28 | 2013-04-30 15:28:20 -0700 | [diff] [blame] | 1050 | threadgroup_change_begin(tsk); |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1051 | write_lock_irq(&tasklist_lock); |
Kirill Tkhai | dfcce79 | 2015-04-16 12:48:01 -0700 | [diff] [blame] | 1052 | /* |
| 1053 | * Do this under tasklist_lock to ensure that |
| 1054 | * exit_notify() can't miss ->group_exit_task |
| 1055 | */ |
| 1056 | sig->notify_count = -1; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1057 | if (likely(leader->exit_state)) |
| 1058 | break; |
Oleg Nesterov | d5bbd43 | 2012-10-08 19:13:01 +0200 | [diff] [blame] | 1059 | __set_current_state(TASK_KILLABLE); |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1060 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | e56fb28 | 2013-04-30 15:28:20 -0700 | [diff] [blame] | 1061 | threadgroup_change_end(tsk); |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1062 | schedule(); |
Oleg Nesterov | d5bbd43 | 2012-10-08 19:13:01 +0200 | [diff] [blame] | 1063 | if (unlikely(__fatal_signal_pending(tsk))) |
| 1064 | goto killed; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1065 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 1067 | /* |
| 1068 | * The only record we have of the real-time age of a |
| 1069 | * process, regardless of execs it's done, is start_time. |
| 1070 | * All the past CPU time is accumulated in signal_struct |
| 1071 | * from sister threads now dead. But in this non-leader |
| 1072 | * exec, nothing survives from the original leader thread, |
| 1073 | * whose birth marks the true age of this process now. |
| 1074 | * When we take on its identity by switching to its PID, we |
| 1075 | * also take its birthdate (always earlier than our own). |
| 1076 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1077 | tsk->start_time = leader->start_time; |
Oleg Nesterov | 266b7a0 | 2013-07-03 15:08:35 -0700 | [diff] [blame] | 1078 | tsk->real_start_time = leader->real_start_time; |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 1079 | |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 1080 | BUG_ON(!same_thread_group(leader, tsk)); |
| 1081 | BUG_ON(has_group_leader_pid(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1082 | /* |
| 1083 | * An exec() starts a new thread group with the |
| 1084 | * TGID of the previous thread group. Rehash the |
| 1085 | * two threads with a switched PID, and release |
| 1086 | * the former thread group leader: |
| 1087 | */ |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 1088 | |
| 1089 | /* Become a process group leader with the old leader's pid. |
Eric W. Biederman | c18258c | 2006-09-27 01:51:06 -0700 | [diff] [blame] | 1090 | * The old leader becomes a thread of the this thread group. |
| 1091 | * Note: The old leader also uses this pid until release_task |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 1092 | * is called. Odd but simple and correct. |
| 1093 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1094 | tsk->pid = leader->pid; |
Oleg Nesterov | 3f41854 | 2013-07-03 15:08:25 -0700 | [diff] [blame] | 1095 | change_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1096 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
| 1097 | transfer_pid(leader, tsk, PIDTYPE_SID); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 1098 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1099 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 1100 | list_replace_init(&leader->sibling, &tsk->sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1102 | tsk->group_leader = tsk; |
| 1103 | leader->group_leader = tsk; |
Eric W. Biederman | de12a78 | 2006-04-10 17:16:49 -0600 | [diff] [blame] | 1104 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1105 | tsk->exit_signal = SIGCHLD; |
Oleg Nesterov | 087806b | 2011-06-22 23:10:26 +0200 | [diff] [blame] | 1106 | leader->exit_signal = -1; |
Oleg Nesterov | 962b564 | 2005-11-23 13:37:43 -0800 | [diff] [blame] | 1107 | |
| 1108 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); |
| 1109 | leader->exit_state = EXIT_DEAD; |
Oleg Nesterov | eac1b5e | 2011-07-21 20:00:43 +0200 | [diff] [blame] | 1110 | |
| 1111 | /* |
| 1112 | * We are going to release_task()->ptrace_unlink() silently, |
| 1113 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees |
| 1114 | * the tracer wont't block again waiting for this thread. |
| 1115 | */ |
| 1116 | if (unlikely(leader->ptrace)) |
| 1117 | __wake_up_parent(leader, leader->parent); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | e56fb28 | 2013-04-30 15:28:20 -0700 | [diff] [blame] | 1119 | threadgroup_change_end(tsk); |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 1120 | |
| 1121 | release_task(leader); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 1122 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 1124 | sig->group_exit_task = NULL; |
| 1125 | sig->notify_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | |
| 1127 | no_thread_group: |
Oleg Nesterov | e636825 | 2012-03-19 17:03:22 +0100 | [diff] [blame] | 1128 | /* we have changed execution domain */ |
| 1129 | tsk->exit_signal = SIGCHLD; |
| 1130 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | exit_itimers(sig); |
Oleg Nesterov | cbaffba | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 1132 | flush_itimer_signals(); |
Oleg Nesterov | 329f7db | 2005-11-07 21:12:43 +0300 | [diff] [blame] | 1133 | |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1134 | if (atomic_read(&oldsighand->count) != 1) { |
| 1135 | struct sighand_struct *newsighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | /* |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1137 | * This ->sighand is shared with the CLONE_SIGHAND |
| 1138 | * but not CLONE_THREAD task, switch to the new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1139 | */ |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1140 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
| 1141 | if (!newsighand) |
| 1142 | return -ENOMEM; |
| 1143 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | atomic_set(&newsighand->count, 1); |
| 1145 | memcpy(newsighand->action, oldsighand->action, |
| 1146 | sizeof(newsighand->action)); |
| 1147 | |
| 1148 | write_lock_irq(&tasklist_lock); |
| 1149 | spin_lock(&oldsighand->siglock); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1150 | rcu_assign_pointer(tsk->sighand, newsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1151 | spin_unlock(&oldsighand->siglock); |
| 1152 | write_unlock_irq(&tasklist_lock); |
| 1153 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 1154 | __cleanup_sighand(oldsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1155 | } |
| 1156 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 1157 | BUG_ON(!thread_group_leader(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | return 0; |
Oleg Nesterov | d5bbd43 | 2012-10-08 19:13:01 +0200 | [diff] [blame] | 1159 | |
| 1160 | killed: |
| 1161 | /* protects against exit_notify() and __exit_signal() */ |
| 1162 | read_lock(&tasklist_lock); |
| 1163 | sig->group_exit_task = NULL; |
| 1164 | sig->notify_count = 0; |
| 1165 | read_unlock(&tasklist_lock); |
| 1166 | return -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | } |
Oleg Nesterov | 0840a90 | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 1168 | |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1169 | char *get_task_comm(char *buf, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | { |
| 1171 | /* buf must be at least sizeof(tsk->comm) in size */ |
| 1172 | task_lock(tsk); |
| 1173 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); |
| 1174 | task_unlock(tsk); |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 1175 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1176 | } |
J Freyensee | 7d74f49 | 2011-05-06 16:56:47 -0700 | [diff] [blame] | 1177 | EXPORT_SYMBOL_GPL(get_task_comm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | |
Al Viro | 6a6d27d | 2012-08-21 09:56:33 -0400 | [diff] [blame] | 1179 | /* |
| 1180 | * These functions flushes out all traces of the currently running executable |
| 1181 | * so that a new one can be started |
| 1182 | */ |
| 1183 | |
Adrian Hunter | 82b8977 | 2014-05-28 11:45:04 +0300 | [diff] [blame] | 1184 | void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1185 | { |
| 1186 | task_lock(tsk); |
KAMEZAWA Hiroyuki | 43d2b11 | 2012-01-10 15:08:09 -0800 | [diff] [blame] | 1187 | trace_task_rename(tsk, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
| 1189 | task_unlock(tsk); |
Adrian Hunter | 82b8977 | 2014-05-28 11:45:04 +0300 | [diff] [blame] | 1190 | perf_event_comm(tsk, exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1191 | } |
| 1192 | |
| 1193 | int flush_old_exec(struct linux_binprm * bprm) |
| 1194 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1195 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | |
| 1197 | /* |
| 1198 | * Make sure we have a private signal table and that |
| 1199 | * we are unassociated from the previous thread group. |
| 1200 | */ |
| 1201 | retval = de_thread(current); |
| 1202 | if (retval) |
| 1203 | goto out; |
| 1204 | |
Davidlohr Bueso | 6e399cd | 2015-04-16 12:47:59 -0700 | [diff] [blame] | 1205 | /* |
| 1206 | * Must be called _before_ exec_mmap() as bprm->mm is |
| 1207 | * not visibile until then. This also enables the update |
| 1208 | * to be lockless. |
| 1209 | */ |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 1210 | set_mm_exe_file(bprm->mm, bprm->file); |
Davidlohr Bueso | 6e399cd | 2015-04-16 12:47:59 -0700 | [diff] [blame] | 1211 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1213 | * Release all of the old mmap stuff |
| 1214 | */ |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1215 | acct_arg_size(bprm, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | retval = exec_mmap(bprm->mm); |
| 1217 | if (retval) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1218 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1219 | |
| 1220 | bprm->mm = NULL; /* We're using it now */ |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1221 | |
Mathias Krause | dac853a | 2011-06-09 20:05:18 +0200 | [diff] [blame] | 1222 | set_fs(USER_DS); |
Zhang Yi | b88fae6 | 2014-01-23 15:55:57 -0800 | [diff] [blame] | 1223 | current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | |
| 1224 | PF_NOFREEZE | PF_NO_SETAFFINITY); |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 1225 | flush_thread(); |
| 1226 | current->personality &= ~bprm->per_clear; |
| 1227 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1228 | return 0; |
| 1229 | |
| 1230 | out: |
| 1231 | return retval; |
| 1232 | } |
| 1233 | EXPORT_SYMBOL(flush_old_exec); |
| 1234 | |
Al Viro | 1b5d783 | 2011-06-19 12:49:47 -0400 | [diff] [blame] | 1235 | void would_dump(struct linux_binprm *bprm, struct file *file) |
| 1236 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 1237 | if (inode_permission(file_inode(file), MAY_READ) < 0) |
Al Viro | 1b5d783 | 2011-06-19 12:49:47 -0400 | [diff] [blame] | 1238 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; |
| 1239 | } |
| 1240 | EXPORT_SYMBOL(would_dump); |
| 1241 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1242 | void setup_new_exec(struct linux_binprm * bprm) |
| 1243 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1244 | arch_pick_mmap_layout(current->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | |
| 1246 | /* This is the point of no return */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1247 | current->sas_ss_sp = current->sas_ss_size = 0; |
| 1248 | |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 1249 | if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid())) |
Kees Cook | e579d2c | 2013-02-27 17:03:15 -0800 | [diff] [blame] | 1250 | set_dumpable(current->mm, SUID_DUMP_USER); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1251 | else |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1252 | set_dumpable(current->mm, suid_dumpable); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1253 | |
Peter Zijlstra | e041e32 | 2014-05-21 17:32:19 +0200 | [diff] [blame] | 1254 | perf_event_exec(); |
Adrian Hunter | 82b8977 | 2014-05-28 11:45:04 +0300 | [diff] [blame] | 1255 | __set_task_comm(current, kbasename(bprm->filename), true); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | |
Benjamin Herrenschmidt | 0551fbd | 2006-02-28 16:59:19 -0800 | [diff] [blame] | 1257 | /* Set the new mm task size. We have to do that late because it may |
| 1258 | * depend on TIF_32BIT which is only updated in flush_thread() on |
| 1259 | * some architectures like powerpc |
| 1260 | */ |
| 1261 | current->mm->task_size = TASK_SIZE; |
| 1262 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1263 | /* install the new credentials */ |
Eric W. Biederman | 8e96e3b | 2012-03-03 21:17:15 -0800 | [diff] [blame] | 1264 | if (!uid_eq(bprm->cred->uid, current_euid()) || |
| 1265 | !gid_eq(bprm->cred->gid, current_egid())) { |
Marcel Holtmann | d2d56c5 | 2007-08-17 21:47:58 +0200 | [diff] [blame] | 1266 | current->pdeath_signal = 0; |
Al Viro | 1b5d783 | 2011-06-19 12:49:47 -0400 | [diff] [blame] | 1267 | } else { |
| 1268 | would_dump(bprm, bprm->file); |
| 1269 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) |
| 1270 | set_dumpable(current->mm, suid_dumpable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | } |
| 1272 | |
| 1273 | /* An exec changes our domain. We are no longer part of the thread |
| 1274 | group */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | current->self_exec_id++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | flush_signal_handlers(current, 0); |
Al Viro | 6a6d27d | 2012-08-21 09:56:33 -0400 | [diff] [blame] | 1277 | do_close_on_exec(current->files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | } |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1279 | EXPORT_SYMBOL(setup_new_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1281 | /* |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1282 | * Prepare credentials and lock ->cred_guard_mutex. |
| 1283 | * install_exec_creds() commits the new creds and drops the lock. |
| 1284 | * Or, if exec fails before, free_bprm() should release ->cred and |
| 1285 | * and unlock. |
| 1286 | */ |
| 1287 | int prepare_bprm_creds(struct linux_binprm *bprm) |
| 1288 | { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1289 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1290 | return -ERESTARTNOINTR; |
| 1291 | |
| 1292 | bprm->cred = prepare_exec_creds(); |
| 1293 | if (likely(bprm->cred)) |
| 1294 | return 0; |
| 1295 | |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1296 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1297 | return -ENOMEM; |
| 1298 | } |
| 1299 | |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1300 | static void free_bprm(struct linux_binprm *bprm) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1301 | { |
| 1302 | free_arg_pages(bprm); |
| 1303 | if (bprm->cred) { |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1304 | mutex_unlock(¤t->signal->cred_guard_mutex); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1305 | abort_creds(bprm->cred); |
| 1306 | } |
Oleg Nesterov | 63e46b9 | 2014-01-23 15:55:51 -0800 | [diff] [blame] | 1307 | if (bprm->file) { |
| 1308 | allow_write_access(bprm->file); |
| 1309 | fput(bprm->file); |
| 1310 | } |
Kees Cook | b66c598 | 2012-12-20 15:05:16 -0800 | [diff] [blame] | 1311 | /* If a binfmt changed the interp, free it. */ |
| 1312 | if (bprm->interp != bprm->filename) |
| 1313 | kfree(bprm->interp); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1314 | kfree(bprm); |
| 1315 | } |
| 1316 | |
Kees Cook | b66c598 | 2012-12-20 15:05:16 -0800 | [diff] [blame] | 1317 | int bprm_change_interp(char *interp, struct linux_binprm *bprm) |
| 1318 | { |
| 1319 | /* If a binfmt changed the interp, free it first. */ |
| 1320 | if (bprm->interp != bprm->filename) |
| 1321 | kfree(bprm->interp); |
| 1322 | bprm->interp = kstrdup(interp, GFP_KERNEL); |
| 1323 | if (!bprm->interp) |
| 1324 | return -ENOMEM; |
| 1325 | return 0; |
| 1326 | } |
| 1327 | EXPORT_SYMBOL(bprm_change_interp); |
| 1328 | |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1329 | /* |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1330 | * install the new credentials for this executable |
| 1331 | */ |
| 1332 | void install_exec_creds(struct linux_binprm *bprm) |
| 1333 | { |
| 1334 | security_bprm_committing_creds(bprm); |
| 1335 | |
| 1336 | commit_creds(bprm->cred); |
| 1337 | bprm->cred = NULL; |
Stephane Eranian | 2976b10 | 2013-06-20 11:36:28 +0200 | [diff] [blame] | 1338 | |
| 1339 | /* |
| 1340 | * Disable monitoring for regular users |
| 1341 | * when executing setuid binaries. Must |
| 1342 | * wait until new credentials are committed |
| 1343 | * by commit_creds() above |
| 1344 | */ |
| 1345 | if (get_dumpable(current->mm) != SUID_DUMP_USER) |
| 1346 | perf_event_exit_task(current); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1347 | /* |
| 1348 | * cred_guard_mutex must be held at least to this point to prevent |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1349 | * ptrace_attach() from altering our determination of the task's |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1350 | * credentials; any time after this it may be unlocked. |
| 1351 | */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1352 | security_bprm_committed_creds(bprm); |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1353 | mutex_unlock(¤t->signal->cred_guard_mutex); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1354 | } |
| 1355 | EXPORT_SYMBOL(install_exec_creds); |
| 1356 | |
| 1357 | /* |
| 1358 | * determine how safe it is to execute the proposed program |
KOSAKI Motohiro | 9b1bf12 | 2010-10-27 15:34:08 -0700 | [diff] [blame] | 1359 | * - the caller must hold ->cred_guard_mutex to protect against |
Kees Cook | c2e1f2e | 2014-06-05 00:23:17 -0700 | [diff] [blame] | 1360 | * PTRACE_ATTACH or seccomp thread-sync |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1361 | */ |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1362 | static void check_unsafe_exec(struct linux_binprm *bprm) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1363 | { |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1364 | struct task_struct *p = current, *t; |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1365 | unsigned n_fs; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1366 | |
Tejun Heo | 4b9d33e | 2011-06-17 16:50:38 +0200 | [diff] [blame] | 1367 | if (p->ptrace) { |
| 1368 | if (p->ptrace & PT_PTRACE_CAP) |
| 1369 | bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; |
| 1370 | else |
| 1371 | bprm->unsafe |= LSM_UNSAFE_PTRACE; |
| 1372 | } |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1373 | |
Andy Lutomirski | 259e5e6 | 2012-04-12 16:47:50 -0500 | [diff] [blame] | 1374 | /* |
| 1375 | * This isn't strictly necessary, but it makes it harder for LSMs to |
| 1376 | * mess up. |
| 1377 | */ |
Kees Cook | 1d4457f | 2014-05-21 15:23:46 -0700 | [diff] [blame] | 1378 | if (task_no_new_privs(current)) |
Andy Lutomirski | 259e5e6 | 2012-04-12 16:47:50 -0500 | [diff] [blame] | 1379 | bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; |
| 1380 | |
Oleg Nesterov | 83f62a2 | 2014-01-23 15:55:49 -0800 | [diff] [blame] | 1381 | t = p; |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1382 | n_fs = 1; |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1383 | spin_lock(&p->fs->lock); |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1384 | rcu_read_lock(); |
Oleg Nesterov | 83f62a2 | 2014-01-23 15:55:49 -0800 | [diff] [blame] | 1385 | while_each_thread(p, t) { |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1386 | if (t->fs == p->fs) |
| 1387 | n_fs++; |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1388 | } |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1389 | rcu_read_unlock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1390 | |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1391 | if (p->fs->users > n_fs) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1392 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1393 | else |
| 1394 | p->fs->in_exec = 1; |
Nick Piggin | 2a4419b | 2010-08-18 04:37:33 +1000 | [diff] [blame] | 1395 | spin_unlock(&p->fs->lock); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1396 | } |
| 1397 | |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1398 | static void bprm_fill_uid(struct linux_binprm *bprm) |
| 1399 | { |
| 1400 | struct inode *inode; |
| 1401 | unsigned int mode; |
| 1402 | kuid_t uid; |
| 1403 | kgid_t gid; |
| 1404 | |
Kees Cook | cb6fd68 | 2016-05-17 12:14:39 -0700 | [diff] [blame] | 1405 | /* |
| 1406 | * Since this can be called multiple times (via prepare_binprm), |
| 1407 | * we must clear any previous work done when setting set[ug]id |
| 1408 | * bits from any earlier bprm->file uses (for example when run |
| 1409 | * first for a setuid script then again for its interpreter). |
| 1410 | */ |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1411 | bprm->cred->euid = current_euid(); |
| 1412 | bprm->cred->egid = current_egid(); |
| 1413 | |
Andy Lutomirski | 380cf5b | 2016-06-23 16:41:05 -0500 | [diff] [blame^] | 1414 | if (!mnt_may_suid(bprm->file->f_path.mnt)) |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1415 | return; |
| 1416 | |
| 1417 | if (task_no_new_privs(current)) |
| 1418 | return; |
| 1419 | |
| 1420 | inode = file_inode(bprm->file); |
| 1421 | mode = READ_ONCE(inode->i_mode); |
| 1422 | if (!(mode & (S_ISUID|S_ISGID))) |
| 1423 | return; |
| 1424 | |
| 1425 | /* Be careful if suid/sgid is set */ |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1426 | inode_lock(inode); |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1427 | |
| 1428 | /* reload atomically mode/uid/gid now that lock held */ |
| 1429 | mode = inode->i_mode; |
| 1430 | uid = inode->i_uid; |
| 1431 | gid = inode->i_gid; |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 1432 | inode_unlock(inode); |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1433 | |
| 1434 | /* We ignore suid/sgid if there are no mappings for them in the ns */ |
| 1435 | if (!kuid_has_mapping(bprm->cred->user_ns, uid) || |
| 1436 | !kgid_has_mapping(bprm->cred->user_ns, gid)) |
| 1437 | return; |
| 1438 | |
| 1439 | if (mode & S_ISUID) { |
| 1440 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1441 | bprm->cred->euid = uid; |
| 1442 | } |
| 1443 | |
| 1444 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
| 1445 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1446 | bprm->cred->egid = gid; |
| 1447 | } |
| 1448 | } |
| 1449 | |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1450 | /* |
| 1451 | * Fill the binprm structure from the inode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1452 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1453 | * |
| 1454 | * This may be called multiple times for binary chains (scripts for example). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1455 | */ |
| 1456 | int prepare_binprm(struct linux_binprm *bprm) |
| 1457 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | int retval; |
| 1459 | |
Jann Horn | 8b01fc8 | 2015-04-19 02:48:39 +0200 | [diff] [blame] | 1460 | bprm_fill_uid(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | |
| 1462 | /* fill in binprm security blob */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1463 | retval = security_bprm_set_creds(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1464 | if (retval) |
| 1465 | return retval; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1466 | bprm->cred_prepared = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1468 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
| 1469 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | } |
| 1471 | |
| 1472 | EXPORT_SYMBOL(prepare_binprm); |
| 1473 | |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1474 | /* |
| 1475 | * Arguments are '\0' separated strings found at the location bprm->p |
| 1476 | * points to; chop off the first by relocating brpm->p to right after |
| 1477 | * the first '\0' encountered. |
| 1478 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1479 | int remove_arg_zero(struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1481 | int ret = 0; |
| 1482 | unsigned long offset; |
| 1483 | char *kaddr; |
| 1484 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1485 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1486 | if (!bprm->argc) |
| 1487 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1489 | do { |
| 1490 | offset = bprm->p & ~PAGE_MASK; |
| 1491 | page = get_arg_page(bprm, bprm->p, 0); |
| 1492 | if (!page) { |
| 1493 | ret = -EFAULT; |
| 1494 | goto out; |
| 1495 | } |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 1496 | kaddr = kmap_atomic(page); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1497 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1498 | for (; offset < PAGE_SIZE && kaddr[offset]; |
| 1499 | offset++, bprm->p++) |
| 1500 | ; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1501 | |
Cong Wang | e8e3c3d | 2011-11-25 23:14:27 +0800 | [diff] [blame] | 1502 | kunmap_atomic(kaddr); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1503 | put_arg_page(page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1504 | } while (offset == PAGE_SIZE); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1505 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1506 | bprm->p++; |
| 1507 | bprm->argc--; |
| 1508 | ret = 0; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1509 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1510 | out: |
| 1511 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1512 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | EXPORT_SYMBOL(remove_arg_zero); |
| 1514 | |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1515 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1516 | /* |
| 1517 | * cycle the list of binary formats handler, until one recognizes the image |
| 1518 | */ |
Al Viro | 3c456bf | 2012-10-20 21:53:31 -0400 | [diff] [blame] | 1519 | int search_binary_handler(struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1520 | { |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1521 | bool need_retry = IS_ENABLED(CONFIG_MODULES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | struct linux_binfmt *fmt; |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1523 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1524 | |
Kees Cook | d740269 | 2012-12-17 16:03:20 -0800 | [diff] [blame] | 1525 | /* This allows 4 levels of binfmt rewrites before failing hard. */ |
Oleg Nesterov | 131b2f9 | 2013-09-11 14:24:39 -0700 | [diff] [blame] | 1526 | if (bprm->recursion_depth > 5) |
Kees Cook | d740269 | 2012-12-17 16:03:20 -0800 | [diff] [blame] | 1527 | return -ELOOP; |
| 1528 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1529 | retval = security_bprm_check(bprm); |
| 1530 | if (retval) |
| 1531 | return retval; |
| 1532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | retval = -ENOENT; |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1534 | retry: |
| 1535 | read_lock(&binfmt_lock); |
| 1536 | list_for_each_entry(fmt, &formats, lh) { |
| 1537 | if (!try_module_get(fmt->module)) |
| 1538 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | read_unlock(&binfmt_lock); |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1540 | bprm->recursion_depth++; |
| 1541 | retval = fmt->load_binary(bprm); |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1542 | read_lock(&binfmt_lock); |
| 1543 | put_binfmt(fmt); |
Al Viro | 19d860a | 2014-05-04 20:11:36 -0400 | [diff] [blame] | 1544 | bprm->recursion_depth--; |
| 1545 | if (retval < 0 && !bprm->mm) { |
| 1546 | /* we got to flush_old_exec() and failed after it */ |
| 1547 | read_unlock(&binfmt_lock); |
| 1548 | force_sigsegv(SIGSEGV, current); |
| 1549 | return retval; |
| 1550 | } |
| 1551 | if (retval != -ENOEXEC || !bprm->file) { |
| 1552 | read_unlock(&binfmt_lock); |
| 1553 | return retval; |
| 1554 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | } |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1556 | read_unlock(&binfmt_lock); |
| 1557 | |
Al Viro | 19d860a | 2014-05-04 20:11:36 -0400 | [diff] [blame] | 1558 | if (need_retry) { |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1559 | if (printable(bprm->buf[0]) && printable(bprm->buf[1]) && |
| 1560 | printable(bprm->buf[2]) && printable(bprm->buf[3])) |
| 1561 | return retval; |
Oleg Nesterov | 4e0621a | 2013-09-11 14:24:45 -0700 | [diff] [blame] | 1562 | if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0) |
| 1563 | return retval; |
Oleg Nesterov | cb7b6b1 | 2013-09-11 14:24:44 -0700 | [diff] [blame] | 1564 | need_retry = false; |
| 1565 | goto retry; |
| 1566 | } |
| 1567 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1568 | return retval; |
| 1569 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1570 | EXPORT_SYMBOL(search_binary_handler); |
| 1571 | |
Oleg Nesterov | 5d1baf3 | 2013-09-11 14:24:38 -0700 | [diff] [blame] | 1572 | static int exec_binprm(struct linux_binprm *bprm) |
| 1573 | { |
| 1574 | pid_t old_pid, old_vpid; |
| 1575 | int ret; |
| 1576 | |
| 1577 | /* Need to fetch pid before load_binary changes it */ |
| 1578 | old_pid = current->pid; |
| 1579 | rcu_read_lock(); |
| 1580 | old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); |
| 1581 | rcu_read_unlock(); |
| 1582 | |
| 1583 | ret = search_binary_handler(bprm); |
| 1584 | if (ret >= 0) { |
Linus Torvalds | 3eaded86 | 2013-11-21 19:18:14 -0800 | [diff] [blame] | 1585 | audit_bprm(bprm); |
Oleg Nesterov | 5d1baf3 | 2013-09-11 14:24:38 -0700 | [diff] [blame] | 1586 | trace_sched_process_exec(current, old_pid, bprm); |
| 1587 | ptrace_event(PTRACE_EVENT_EXEC, old_vpid); |
Oleg Nesterov | 9beb266 | 2013-09-11 14:24:40 -0700 | [diff] [blame] | 1588 | proc_exec_connector(current); |
Oleg Nesterov | 5d1baf3 | 2013-09-11 14:24:38 -0700 | [diff] [blame] | 1589 | } |
| 1590 | |
| 1591 | return ret; |
| 1592 | } |
| 1593 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | /* |
| 1595 | * sys_execve() executes a new program. |
| 1596 | */ |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1597 | static int do_execveat_common(int fd, struct filename *filename, |
| 1598 | struct user_arg_ptr argv, |
| 1599 | struct user_arg_ptr envp, |
| 1600 | int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1601 | { |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1602 | char *pathbuf = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | struct linux_binprm *bprm; |
| 1604 | struct file *file; |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1605 | struct files_struct *displaced; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1606 | int retval; |
Vasiliy Kulikov | 72fa599 | 2011-08-08 19:02:04 +0400 | [diff] [blame] | 1607 | |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1608 | if (IS_ERR(filename)) |
| 1609 | return PTR_ERR(filename); |
| 1610 | |
Vasiliy Kulikov | 72fa599 | 2011-08-08 19:02:04 +0400 | [diff] [blame] | 1611 | /* |
| 1612 | * We move the actual failure in case of RLIMIT_NPROC excess from |
| 1613 | * set*uid() to execve() because too many poorly written programs |
| 1614 | * don't check setuid() return code. Here we additionally recheck |
| 1615 | * whether NPROC limit is still exceeded. |
| 1616 | */ |
| 1617 | if ((current->flags & PF_NPROC_EXCEEDED) && |
Oleg Nesterov | bd9d43f | 2013-07-03 15:08:34 -0700 | [diff] [blame] | 1618 | atomic_read(¤t_user()->processes) > rlimit(RLIMIT_NPROC)) { |
Vasiliy Kulikov | 72fa599 | 2011-08-08 19:02:04 +0400 | [diff] [blame] | 1619 | retval = -EAGAIN; |
| 1620 | goto out_ret; |
| 1621 | } |
| 1622 | |
| 1623 | /* We're below the limit (still or again), so we don't want to make |
| 1624 | * further execve() calls fail. */ |
| 1625 | current->flags &= ~PF_NPROC_EXCEEDED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1627 | retval = unshare_files(&displaced); |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1628 | if (retval) |
| 1629 | goto out_ret; |
| 1630 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1631 | retval = -ENOMEM; |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 1632 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1633 | if (!bprm) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1634 | goto out_files; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1636 | retval = prepare_bprm_creds(bprm); |
| 1637 | if (retval) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1638 | goto out_free; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1639 | |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1640 | check_unsafe_exec(bprm); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1641 | current->in_execve = 1; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1642 | |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1643 | file = do_open_execat(fd, filename, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | retval = PTR_ERR(file); |
| 1645 | if (IS_ERR(file)) |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1646 | goto out_unmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | |
| 1648 | sched_exec(); |
| 1649 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | bprm->file = file; |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1651 | if (fd == AT_FDCWD || filename->name[0] == '/') { |
| 1652 | bprm->filename = filename->name; |
| 1653 | } else { |
| 1654 | if (filename->name[0] == '\0') |
| 1655 | pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d", fd); |
| 1656 | else |
| 1657 | pathbuf = kasprintf(GFP_TEMPORARY, "/dev/fd/%d/%s", |
| 1658 | fd, filename->name); |
| 1659 | if (!pathbuf) { |
| 1660 | retval = -ENOMEM; |
| 1661 | goto out_unmark; |
| 1662 | } |
| 1663 | /* |
| 1664 | * Record that a name derived from an O_CLOEXEC fd will be |
| 1665 | * inaccessible after exec. Relies on having exclusive access to |
| 1666 | * current->files (due to unshare_files above). |
| 1667 | */ |
| 1668 | if (close_on_exec(fd, rcu_dereference_raw(current->files->fdt))) |
| 1669 | bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; |
| 1670 | bprm->filename = pathbuf; |
| 1671 | } |
| 1672 | bprm->interp = bprm->filename; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1673 | |
| 1674 | retval = bprm_mm_init(bprm); |
| 1675 | if (retval) |
Oleg Nesterov | 63e46b9 | 2014-01-23 15:55:51 -0800 | [diff] [blame] | 1676 | goto out_unmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1677 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1678 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | if ((retval = bprm->argc) < 0) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1680 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1681 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1682 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1683 | if ((retval = bprm->envc) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1684 | goto out; |
| 1685 | |
| 1686 | retval = prepare_binprm(bprm); |
| 1687 | if (retval < 0) |
| 1688 | goto out; |
| 1689 | |
| 1690 | retval = copy_strings_kernel(1, &bprm->filename, bprm); |
| 1691 | if (retval < 0) |
| 1692 | goto out; |
| 1693 | |
| 1694 | bprm->exec = bprm->p; |
| 1695 | retval = copy_strings(bprm->envc, envp, bprm); |
| 1696 | if (retval < 0) |
| 1697 | goto out; |
| 1698 | |
| 1699 | retval = copy_strings(bprm->argc, argv, bprm); |
| 1700 | if (retval < 0) |
| 1701 | goto out; |
| 1702 | |
Oleg Nesterov | 5d1baf3 | 2013-09-11 14:24:38 -0700 | [diff] [blame] | 1703 | retval = exec_binprm(bprm); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1704 | if (retval < 0) |
| 1705 | goto out; |
| 1706 | |
| 1707 | /* execve succeeded */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1708 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1709 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1710 | acct_update_integrals(current); |
Rik van Riel | 8272701 | 2013-10-07 11:29:28 +0100 | [diff] [blame] | 1711 | task_numa_free(current); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1712 | free_bprm(bprm); |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1713 | kfree(pathbuf); |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1714 | putname(filename); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1715 | if (displaced) |
| 1716 | put_files_struct(displaced); |
| 1717 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1718 | |
| 1719 | out: |
Oleg Nesterov | 3c77f84 | 2010-11-30 20:55:34 +0100 | [diff] [blame] | 1720 | if (bprm->mm) { |
| 1721 | acct_arg_size(bprm, 0); |
| 1722 | mmput(bprm->mm); |
| 1723 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1725 | out_unmark: |
Oleg Nesterov | 9e00cdb | 2014-01-23 15:55:50 -0800 | [diff] [blame] | 1726 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1727 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1728 | |
| 1729 | out_free: |
Al Viro | 08a6fac | 2008-05-10 16:38:25 -0400 | [diff] [blame] | 1730 | free_bprm(bprm); |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1731 | kfree(pathbuf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1732 | |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1733 | out_files: |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1734 | if (displaced) |
| 1735 | reset_files_struct(displaced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1736 | out_ret: |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1737 | putname(filename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1738 | return retval; |
| 1739 | } |
| 1740 | |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1741 | int do_execve(struct filename *filename, |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1742 | const char __user *const __user *__argv, |
Al Viro | da3d4c5 | 2012-10-20 21:49:33 -0400 | [diff] [blame] | 1743 | const char __user *const __user *__envp) |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1744 | { |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1745 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
| 1746 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1747 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
| 1748 | } |
| 1749 | |
| 1750 | int do_execveat(int fd, struct filename *filename, |
| 1751 | const char __user *const __user *__argv, |
| 1752 | const char __user *const __user *__envp, |
| 1753 | int flags) |
| 1754 | { |
| 1755 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
| 1756 | struct user_arg_ptr envp = { .ptr.native = __envp }; |
| 1757 | |
| 1758 | return do_execveat_common(fd, filename, argv, envp, flags); |
Oleg Nesterov | ba2d0162 | 2011-03-06 18:02:37 +0100 | [diff] [blame] | 1759 | } |
| 1760 | |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1761 | #ifdef CONFIG_COMPAT |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1762 | static int compat_do_execve(struct filename *filename, |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1763 | const compat_uptr_t __user *__argv, |
Al Viro | d03d26e | 2012-10-20 21:46:25 -0400 | [diff] [blame] | 1764 | const compat_uptr_t __user *__envp) |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1765 | { |
| 1766 | struct user_arg_ptr argv = { |
| 1767 | .is_compat = true, |
| 1768 | .ptr.compat = __argv, |
| 1769 | }; |
| 1770 | struct user_arg_ptr envp = { |
| 1771 | .is_compat = true, |
| 1772 | .ptr.compat = __envp, |
| 1773 | }; |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1774 | return do_execveat_common(AT_FDCWD, filename, argv, envp, 0); |
| 1775 | } |
| 1776 | |
| 1777 | static int compat_do_execveat(int fd, struct filename *filename, |
| 1778 | const compat_uptr_t __user *__argv, |
| 1779 | const compat_uptr_t __user *__envp, |
| 1780 | int flags) |
| 1781 | { |
| 1782 | struct user_arg_ptr argv = { |
| 1783 | .is_compat = true, |
| 1784 | .ptr.compat = __argv, |
| 1785 | }; |
| 1786 | struct user_arg_ptr envp = { |
| 1787 | .is_compat = true, |
| 1788 | .ptr.compat = __envp, |
| 1789 | }; |
| 1790 | return do_execveat_common(fd, filename, argv, envp, flags); |
Oleg Nesterov | 0e02846 | 2011-03-06 18:02:54 +0100 | [diff] [blame] | 1791 | } |
| 1792 | #endif |
| 1793 | |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1794 | void set_binfmt(struct linux_binfmt *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1795 | { |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1796 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1797 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1798 | if (mm->binfmt) |
| 1799 | module_put(mm->binfmt->module); |
| 1800 | |
| 1801 | mm->binfmt = new; |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1802 | if (new) |
| 1803 | __module_get(new->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1804 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | EXPORT_SYMBOL(set_binfmt); |
| 1806 | |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1807 | /* |
Oleg Nesterov | 7288e11 | 2014-01-23 15:55:32 -0800 | [diff] [blame] | 1808 | * set_dumpable stores three-value SUID_DUMP_* into mm->flags. |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1809 | */ |
| 1810 | void set_dumpable(struct mm_struct *mm, int value) |
| 1811 | { |
Oleg Nesterov | abacd2f | 2014-01-23 15:55:31 -0800 | [diff] [blame] | 1812 | unsigned long old, new; |
| 1813 | |
Oleg Nesterov | 7288e11 | 2014-01-23 15:55:32 -0800 | [diff] [blame] | 1814 | if (WARN_ON((unsigned)value > SUID_DUMP_ROOT)) |
| 1815 | return; |
| 1816 | |
Oleg Nesterov | abacd2f | 2014-01-23 15:55:31 -0800 | [diff] [blame] | 1817 | do { |
| 1818 | old = ACCESS_ONCE(mm->flags); |
Oleg Nesterov | 7288e11 | 2014-01-23 15:55:32 -0800 | [diff] [blame] | 1819 | new = (old & ~MMF_DUMPABLE_MASK) | value; |
Oleg Nesterov | abacd2f | 2014-01-23 15:55:31 -0800 | [diff] [blame] | 1820 | } while (cmpxchg(&mm->flags, old, new) != old); |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1821 | } |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1822 | |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1823 | SYSCALL_DEFINE3(execve, |
| 1824 | const char __user *, filename, |
| 1825 | const char __user *const __user *, argv, |
| 1826 | const char __user *const __user *, envp) |
| 1827 | { |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1828 | return do_execve(getname(filename), argv, envp); |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1829 | } |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1830 | |
| 1831 | SYSCALL_DEFINE5(execveat, |
| 1832 | int, fd, const char __user *, filename, |
| 1833 | const char __user *const __user *, argv, |
| 1834 | const char __user *const __user *, envp, |
| 1835 | int, flags) |
| 1836 | { |
| 1837 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; |
| 1838 | |
| 1839 | return do_execveat(fd, |
| 1840 | getname_flags(filename, lookup_flags, NULL), |
| 1841 | argv, envp, flags); |
| 1842 | } |
| 1843 | |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1844 | #ifdef CONFIG_COMPAT |
Heiko Carstens | 625b1d7 | 2014-03-04 10:53:50 +0100 | [diff] [blame] | 1845 | COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, |
| 1846 | const compat_uptr_t __user *, argv, |
| 1847 | const compat_uptr_t __user *, envp) |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1848 | { |
Linus Torvalds | c4ad8f9 | 2014-02-05 12:54:53 -0800 | [diff] [blame] | 1849 | return compat_do_execve(getname(filename), argv, envp); |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1850 | } |
David Drysdale | 51f39a1 | 2014-12-12 16:57:29 -0800 | [diff] [blame] | 1851 | |
| 1852 | COMPAT_SYSCALL_DEFINE5(execveat, int, fd, |
| 1853 | const char __user *, filename, |
| 1854 | const compat_uptr_t __user *, argv, |
| 1855 | const compat_uptr_t __user *, envp, |
| 1856 | int, flags) |
| 1857 | { |
| 1858 | int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0; |
| 1859 | |
| 1860 | return compat_do_execveat(fd, |
| 1861 | getname_flags(filename, lookup_flags, NULL), |
| 1862 | argv, envp, flags); |
| 1863 | } |
Al Viro | 38b983b | 2012-09-30 13:38:55 -0400 | [diff] [blame] | 1864 | #endif |