CRED: Wrap task credential accesses in the core kernel
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-audit@redhat.com
Cc: containers@lists.linux-foundation.org
Cc: linux-mm@kvack.org
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/kernel/acct.c b/kernel/acct.c
index f6006a6..d57b7cb 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -530,15 +530,14 @@
do_div(elapsed, AHZ);
ac.ac_btime = get_seconds() - elapsed;
/* we really need to bite the bullet and change layout */
- ac.ac_uid = current->uid;
- ac.ac_gid = current->gid;
+ current_uid_gid(&ac.ac_uid, &ac.ac_gid);
#if ACCT_VERSION==2
ac.ac_ahz = AHZ;
#endif
#if ACCT_VERSION==1 || ACCT_VERSION==2
/* backward-compatible 16 bit fields */
- ac.ac_uid16 = current->uid;
- ac.ac_gid16 = current->gid;
+ ac.ac_uid16 = ac.ac_uid;
+ ac.ac_gid16 = ac.ac_gid;
#endif
#if ACCT_VERSION==3
ac.ac_pid = task_tgid_nr_ns(current, ns);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index cef3423..9c7e47a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2628,7 +2628,8 @@
{
struct audit_buffer *ab;
u32 sid;
- uid_t auid = audit_get_loginuid(current);
+ uid_t auid = audit_get_loginuid(current), uid;
+ gid_t gid;
unsigned int sessionid = audit_get_sessionid(current);
if (!audit_enabled)
@@ -2638,8 +2639,9 @@
return;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
+ current_uid_gid(&uid, &gid);
audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
- auid, current->uid, current->gid, sessionid);
+ auid, uid, gid, sessionid);
security_task_getsecid(current, &sid);
if (sid) {
char *ctx = NULL;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 35eebd5..78f9b31 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -571,8 +571,8 @@
if (inode) {
inode->i_mode = mode;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_mapping->backing_dev_info = &cgroup_backing_dev_info;
@@ -1279,6 +1279,7 @@
static int attach_task_by_pid(struct cgroup *cgrp, u64 pid)
{
struct task_struct *tsk;
+ uid_t euid;
int ret;
if (pid) {
@@ -1291,8 +1292,8 @@
get_task_struct(tsk);
rcu_read_unlock();
- if ((current->euid) && (current->euid != tsk->uid)
- && (current->euid != tsk->suid)) {
+ euid = current_euid();
+ if (euid && euid != tsk->uid && euid != tsk->suid) {
put_task_struct(tsk);
return -EACCES;
}
diff --git a/kernel/futex.c b/kernel/futex.c
index 8af1002..e069621 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -439,10 +439,11 @@
static struct task_struct * futex_find_get_task(pid_t pid)
{
struct task_struct *p;
+ uid_t euid = current_euid();
rcu_read_lock();
p = find_task_by_vpid(pid);
- if (!p || ((current->euid != p->euid) && (current->euid != p->uid)))
+ if (!p || (euid != p->euid && euid != p->uid))
p = ERR_PTR(-ESRCH);
else
get_task_struct(p);
@@ -1829,6 +1830,7 @@
{
struct robust_list_head __user *head;
unsigned long ret;
+ uid_t euid = current_euid();
if (!futex_cmpxchg_enabled)
return -ENOSYS;
@@ -1844,8 +1846,8 @@
if (!p)
goto err_unlock;
ret = -EPERM;
- if ((current->euid != p->euid) && (current->euid != p->uid) &&
- !capable(CAP_SYS_PTRACE))
+ if (euid != p->euid && euid != p->uid &&
+ !capable(CAP_SYS_PTRACE))
goto err_unlock;
head = p->robust_list;
rcu_read_unlock();
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 04ac3a9..3254d4e 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -135,6 +135,7 @@
{
struct compat_robust_list_head __user *head;
unsigned long ret;
+ uid_t euid = current_euid();
if (!futex_cmpxchg_enabled)
return -ENOSYS;
@@ -150,7 +151,7 @@
if (!p)
goto err_unlock;
ret = -EPERM;
- if ((current->euid != p->euid) && (current->euid != p->uid) &&
+ if (euid != p->euid && euid != p->uid &&
!capable(CAP_SYS_PTRACE))
goto err_unlock;
head = p->compat_robust_list;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1e68e4c..937f6b5 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -123,16 +123,19 @@
* because setting up the necessary parent/child relationship
* or halting the specified task is impossible.
*/
+ uid_t uid;
+ gid_t gid;
int dumpable = 0;
/* Don't let security modules deny introspection */
if (task == current)
return 0;
- if (((current->uid != task->euid) ||
- (current->uid != task->suid) ||
- (current->uid != task->uid) ||
- (current->gid != task->egid) ||
- (current->gid != task->sgid) ||
- (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
+ current_uid_gid(&uid, &gid);
+ if ((uid != task->euid ||
+ uid != task->suid ||
+ uid != task->uid ||
+ gid != task->egid ||
+ gid != task->sgid ||
+ gid != task->gid) && !capable(CAP_SYS_PTRACE))
return -EPERM;
smp_rmb();
if (task->mm)
diff --git a/kernel/sched.c b/kernel/sched.c
index e8819bc..c3b8b1f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5128,6 +5128,7 @@
unsigned long flags;
const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
+ uid_t euid;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
@@ -5180,8 +5181,9 @@
return -EPERM;
/* can't change other user's priorities */
- if ((current->euid != p->euid) &&
- (current->euid != p->uid))
+ euid = current_euid();
+ if (euid != p->euid &&
+ euid != p->uid)
return -EPERM;
}
@@ -5392,6 +5394,7 @@
cpumask_t cpus_allowed;
cpumask_t new_mask = *in_mask;
struct task_struct *p;
+ uid_t euid;
int retval;
get_online_cpus();
@@ -5412,9 +5415,9 @@
get_task_struct(p);
read_unlock(&tasklist_lock);
+ euid = current_euid();
retval = -EPERM;
- if ((current->euid != p->euid) && (current->euid != p->uid) &&
- !capable(CAP_SYS_NICE))
+ if (euid != p->euid && euid != p->uid && !capable(CAP_SYS_NICE))
goto out_unlock;
retval = security_task_setscheduler(p, 0, NULL);
diff --git a/kernel/signal.c b/kernel/signal.c
index 4530fc6..167b535 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -567,6 +567,7 @@
struct task_struct *t)
{
struct pid *sid;
+ uid_t uid, euid;
int error;
if (!valid_signal(sig))
@@ -579,8 +580,10 @@
if (error)
return error;
- if ((current->euid ^ t->suid) && (current->euid ^ t->uid) &&
- (current->uid ^ t->suid) && (current->uid ^ t->uid) &&
+ uid = current_uid();
+ euid = current_euid();
+ if ((euid ^ t->suid) && (euid ^ t->uid) &&
+ (uid ^ t->suid) && (uid ^ t->uid) &&
!capable(CAP_KILL)) {
switch (sig) {
case SIGCONT:
@@ -844,7 +847,7 @@
q->info.si_errno = 0;
q->info.si_code = SI_USER;
q->info.si_pid = task_pid_vnr(current);
- q->info.si_uid = current->uid;
+ q->info.si_uid = current_uid();
break;
case (unsigned long) SEND_SIG_PRIV:
q->info.si_signo = sig;
@@ -1598,7 +1601,7 @@
info.si_signo = SIGTRAP;
info.si_code = exit_code;
info.si_pid = task_pid_vnr(current);
- info.si_uid = current->uid;
+ info.si_uid = current_uid();
/* Let the debugger run. */
spin_lock_irq(¤t->sighand->siglock);
@@ -2211,7 +2214,7 @@
info.si_errno = 0;
info.si_code = SI_USER;
info.si_pid = task_tgid_vnr(current);
- info.si_uid = current->uid;
+ info.si_uid = current_uid();
return kill_something_info(sig, &info, pid);
}
@@ -2228,7 +2231,7 @@
info.si_errno = 0;
info.si_code = SI_TKILL;
info.si_pid = task_tgid_vnr(current);
- info.si_uid = current->uid;
+ info.si_uid = current_uid();
rcu_read_lock();
p = find_task_by_vpid(pid);
diff --git a/kernel/sys.c b/kernel/sys.c
index 31deba8..ed5c29c 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -114,10 +114,10 @@
static int set_one_prio(struct task_struct *p, int niceval, int error)
{
+ uid_t euid = current_euid();
int no_nice;
- if (p->uid != current->euid &&
- p->euid != current->euid && !capable(CAP_SYS_NICE)) {
+ if (p->uid != euid && p->euid != euid && !capable(CAP_SYS_NICE)) {
error = -EPERM;
goto out;
}
@@ -176,16 +176,16 @@
case PRIO_USER:
user = current->user;
if (!who)
- who = current->uid;
+ who = current_uid();
else
- if ((who != current->uid) && !(user = find_user(who)))
+ if (who != current_uid() && !(user = find_user(who)))
goto out_unlock; /* No processes for this user */
do_each_thread(g, p)
if (p->uid == who)
error = set_one_prio(p, niceval, error);
while_each_thread(g, p);
- if (who != current->uid)
+ if (who != current_uid())
free_uid(user); /* For find_user() */
break;
}
@@ -238,9 +238,9 @@
case PRIO_USER:
user = current->user;
if (!who)
- who = current->uid;
+ who = current_uid();
else
- if ((who != current->uid) && !(user = find_user(who)))
+ if (who != current_uid() && !(user = find_user(who)))
goto out_unlock; /* No processes for this user */
do_each_thread(g, p)
@@ -250,7 +250,7 @@
retval = niceval;
}
while_each_thread(g, p);
- if (who != current->uid)
+ if (who != current_uid())
free_uid(user); /* for find_user() */
break;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9d048fa..5110313 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1641,7 +1641,7 @@
static int test_perm(int mode, int op)
{
- if (!current->euid)
+ if (!current_euid())
mode >>= 6;
else if (in_egroup_p(0))
mode >>= 3;
diff --git a/kernel/timer.c b/kernel/timer.c
index 56becf3..b54e464 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1123,25 +1123,25 @@
asmlinkage long sys_getuid(void)
{
/* Only we change this so SMP safe */
- return current->uid;
+ return current_uid();
}
asmlinkage long sys_geteuid(void)
{
/* Only we change this so SMP safe */
- return current->euid;
+ return current_euid();
}
asmlinkage long sys_getgid(void)
{
/* Only we change this so SMP safe */
- return current->gid;
+ return current_gid();
}
asmlinkage long sys_getegid(void)
{
/* Only we change this so SMP safe */
- return current->egid;
+ return current_egid();
}
#endif
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 532858f..f82730a 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -38,7 +38,7 @@
}
/* Reset current->user with a new one */
- new_user = alloc_uid(ns, current->uid);
+ new_user = alloc_uid(ns, current_uid());
if (!new_user) {
free_uid(ns->root_user);
kfree(ns);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 36f4257..07a9647 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1115,6 +1115,7 @@
nodemask_t old;
nodemask_t new;
nodemask_t task_nodes;
+ uid_t uid, euid;
int err;
err = get_nodes(&old, old_nodes, maxnode);
@@ -1144,8 +1145,10 @@
* capabilities, superuser privileges or the same
* userid as the target process.
*/
- if ((current->euid != task->suid) && (current->euid != task->uid) &&
- (current->uid != task->suid) && (current->uid != task->uid) &&
+ uid = current_uid();
+ euid = current_euid();
+ if (euid != task->suid && euid != task->uid &&
+ uid != task->suid && uid != task->uid &&
!capable(CAP_SYS_NICE)) {
err = -EPERM;
goto out;
diff --git a/mm/migrate.c b/mm/migrate.c
index 6602941..6263c24 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1048,6 +1048,7 @@
struct task_struct *task;
struct mm_struct *mm;
int err;
+ uid_t uid, euid;
/* Check flags */
if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
@@ -1075,8 +1076,10 @@
* capabilities, superuser privileges or the same
* userid as the target process.
*/
- if ((current->euid != task->suid) && (current->euid != task->uid) &&
- (current->uid != task->suid) && (current->uid != task->uid) &&
+ uid = current_uid();
+ euid = current_euid();
+ if (euid != task->suid && euid != task->uid &&
+ uid != task->suid && uid != task->uid &&
!capable(CAP_SYS_NICE)) {
err = -EPERM;
goto out;
diff --git a/mm/shmem.c b/mm/shmem.c
index 0ed0752..f1b0d48 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1513,8 +1513,8 @@
inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -2278,8 +2278,8 @@
sbinfo->max_blocks = 0;
sbinfo->max_inodes = 0;
sbinfo->mode = S_IRWXUGO | S_ISVTX;
- sbinfo->uid = current->fsuid;
- sbinfo->gid = current->fsgid;
+ sbinfo->uid = current_fsuid();
+ sbinfo->gid = current_fsgid();
sbinfo->mpol = NULL;
sb->s_fs_info = sbinfo;