diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2011-02-07 13:36:10 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-03-02 09:46:39 -0500 |
| commit | 016d370ba62b783a81defeb01aff2ea23d28c28a (patch) | |
| tree | b61e76b8ead4b31a6ee86ffa99b1b96a3c70f0c5 /security | |
| parent | 1c0cd1eb0fff83be95a3fcec991ba4f1b09ff18b (diff) | |
CRED: Fix BUG() upon security_cred_alloc_blank() failure
commit 2edeaa34a6e3f2c43b667f6c4f7b27944b811695 upstream.
In cred_alloc_blank() since 2.6.32, abort_creds(new) is called with
new->security == NULL and new->magic == 0 when security_cred_alloc_blank()
returns an error. As a result, BUG() will be triggered if SELinux is enabled
or CONFIG_DEBUG_CREDENTIALS=y.
If CONFIG_DEBUG_CREDENTIALS=y, BUG() is called from __invalid_creds() because
cred->magic == 0. Failing that, BUG() is called from selinux_cred_free()
because selinux_cred_free() is not expecting cred->security == NULL. This does
not affect smack_cred_free(), tomoyo_cred_free() or apparmor_cred_free().
Fix these bugs by
(1) Set new->magic before calling security_cred_alloc_blank().
(2) Handle null cred->security in creds_are_invalid() and selinux_cred_free().
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0b90dc9f0fe2..a1067544c86b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3262,7 +3262,11 @@ static void selinux_cred_free(struct cred *cred) { struct task_security_struct *tsec = cred->security; - BUG_ON((unsigned long) cred->security < PAGE_SIZE); + /* + * cred->security == NULL if security_cred_alloc_blank() or + * security_prepare_creds() returned an error. + */ + BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); cred->security = (void *) 0x7UL; kfree(tsec); } |