| From | Paul Gortmaker <> | Subject | [34-longterm 099/247] CRED: Fix memory and refcount leaks upon security_prepare_creds() failure | Date | Thu, 23 Jun 2011 13:32:47 -0400 |
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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
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> --- kernel/cred.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
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
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