| From | Andi Kleen <> | Subject | [PATCH] [121/275] CRED: Fix memory and refcount leaks upon security_prepare_creds() failure | Date | Wed, 30 Mar 2011 14:06:01 -0700 (PDT) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
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: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
--- kernel/cred.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
Index: linux-2.6.35.y/kernel/cred.c =================================================================== --- linux-2.6.35.y.orig/kernel/cred.c 2011-03-29 23:03:00.710281996 -0700 +++ linux-2.6.35.y/kernel/cred.c 2011-03-29 23:03:00.732281432 -0700 @@ -663,6 +663,8 @@ 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); @@ -680,8 +682,6 @@ 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;
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