| From 22d18fb084e311e957b0a885990634d66b565fed Mon Sep 17 00:00:00 2001 |
| From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
| Date: Mon, 7 Feb 2011 13:36:16 +0000 |
| Subject: [PATCH] CRED: Fix memory and refcount leaks upon |
| security_prepare_creds() failure |
| |
| commit fb2b2a1d37f80cc818fd4487b510f4e11816e5e1 upstream. |
| |
| In prepare_kernel_cred() since 2.6.29, put_cred(new) is called without |
| assigning new->usage when security_prepare_creds() returned an error. As a |
| result, memory for new and refcount for new->{user,group_info,tgcred} are |
| leaked because put_cred(new) won't call __put_cred() unless old->usage == 1. |
| |
| Fix these leaks by assigning new->usage (and new->subscribers which was added |
| in 2.6.32) before calling security_prepare_creds(). |
| |
| 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/kernel/cred.c b/kernel/cred.c |
| index 9a85aee..aa66d6f 100644 |
| --- a/kernel/cred.c |
| +++ b/kernel/cred.c |
| @@ -725,6 +725,8 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) |
| validate_creds(old); |
| |
| *new = *old; |
| + atomic_set(&new->usage, 1); |
| + set_cred_subscribers(new, 0); |
| get_uid(new->user); |
| get_group_info(new->group_info); |
| |
| @@ -742,8 +744,6 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) |
| if (security_prepare_creds(new, old, GFP_KERNEL) < 0) |
| goto error; |
| |
| - atomic_set(&new->usage, 1); |
| - set_cred_subscribers(new, 0); |
| put_cred(old); |
| validate_creds(new); |
| return new; |
| -- |
| 1.7.4.4 |
| |