TOMOYO: Allow using argv[]/envp[] of execve() as conditions.
This patch adds support for permission checks using argv[]/envp[] of execve()
request. Hooks are in the last patch of this pathset.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index b33a20a..eefedd9 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -10,6 +10,104 @@
#include <linux/slab.h>
/**
+ * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
+ *
+ * @bprm: Pointer to "struct linux_binprm".
+ * @dump: Pointer to "struct tomoyo_page_dump".
+ *
+ * Returns the contents of @bprm on success, NULL otherwise.
+ *
+ * This function uses kzalloc(), so caller must kfree() if this function
+ * didn't return NULL.
+ */
+static char *tomoyo_print_bprm(struct linux_binprm *bprm,
+ struct tomoyo_page_dump *dump)
+{
+ static const int tomoyo_buffer_len = 4096 * 2;
+ char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
+ char *cp;
+ char *last_start;
+ int len;
+ unsigned long pos = bprm->p;
+ int offset = pos % PAGE_SIZE;
+ int argv_count = bprm->argc;
+ int envp_count = bprm->envc;
+ bool truncated = false;
+ if (!buffer)
+ return NULL;
+ len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
+ cp = buffer + len;
+ if (!argv_count) {
+ memmove(cp, "} envp[]={ ", 11);
+ cp += 11;
+ }
+ last_start = cp;
+ while (argv_count || envp_count) {
+ if (!tomoyo_dump_page(bprm, pos, dump))
+ goto out;
+ pos += PAGE_SIZE - offset;
+ /* Read. */
+ while (offset < PAGE_SIZE) {
+ const char *kaddr = dump->data;
+ const unsigned char c = kaddr[offset++];
+ if (cp == last_start)
+ *cp++ = '"';
+ if (cp >= buffer + tomoyo_buffer_len - 32) {
+ /* Reserve some room for "..." string. */
+ truncated = true;
+ } else if (c == '\\') {
+ *cp++ = '\\';
+ *cp++ = '\\';
+ } else if (c > ' ' && c < 127) {
+ *cp++ = c;
+ } else if (!c) {
+ *cp++ = '"';
+ *cp++ = ' ';
+ last_start = cp;
+ } else {
+ *cp++ = '\\';
+ *cp++ = (c >> 6) + '0';
+ *cp++ = ((c >> 3) & 7) + '0';
+ *cp++ = (c & 7) + '0';
+ }
+ if (c)
+ continue;
+ if (argv_count) {
+ if (--argv_count == 0) {
+ if (truncated) {
+ cp = last_start;
+ memmove(cp, "... ", 4);
+ cp += 4;
+ }
+ memmove(cp, "} envp[]={ ", 11);
+ cp += 11;
+ last_start = cp;
+ truncated = false;
+ }
+ } else if (envp_count) {
+ if (--envp_count == 0) {
+ if (truncated) {
+ cp = last_start;
+ memmove(cp, "... ", 4);
+ cp += 4;
+ }
+ }
+ }
+ if (!argv_count && !envp_count)
+ break;
+ }
+ offset = 0;
+ }
+ *cp++ = '}';
+ *cp = '\0';
+ return buffer;
+out:
+ snprintf(buffer, tomoyo_buffer_len - 1,
+ "argv[]={ ... } envp[]= { ... }");
+ return buffer;
+}
+
+/**
* tomoyo_filetype - Get string representation of file type.
*
* @mode: Mode value for stat().
@@ -139,6 +237,7 @@
va_list args)
{
char *buf = NULL;
+ char *bprm_info = NULL;
const char *header = NULL;
char *realpath = NULL;
const char *symlink = NULL;
@@ -152,10 +251,11 @@
if (r->ee) {
struct file *file = r->ee->bprm->file;
realpath = tomoyo_realpath_from_path(&file->f_path);
- if (!realpath)
+ bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
+ if (!realpath || !bprm_info)
goto out;
- /* +80 is for " exec={ realpath=\"%s\" }" */
- len += strlen(realpath) + 80;
+ /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
+ len += strlen(realpath) + 80 + strlen(bprm_info);
} else if (r->obj && r->obj->symlink_target) {
symlink = r->obj->symlink_target->name;
/* +18 is for " symlink.target=\"%s\"" */
@@ -168,8 +268,10 @@
len--;
pos = snprintf(buf, len, "%s", header);
if (realpath) {
+ struct linux_binprm *bprm = r->ee->bprm;
pos += snprintf(buf + pos, len - pos,
- " exec={ realpath=\"%s\" }", realpath);
+ " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
+ realpath, bprm->argc, bprm->envc, bprm_info);
} else if (symlink)
pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
symlink);
@@ -177,6 +279,7 @@
vsnprintf(buf + pos, len - pos, fmt, args);
out:
kfree(realpath);
+ kfree(bprm_info);
kfree(header);
return buf;
}