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CRED: Fix memory and refcount leaks upon security_prepare_creds() failure

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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>
This commit is contained in:
Tetsuo Handa
2011-02-07 13:36:16 +00:00
committed by Linus Torvalds
parent 2edeaa34a6
commit fb2b2a1d37
1 changed files with 2 additions and 2 deletions
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4
kernel/cred.c
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@@ -657,6 +657,8 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
validate_creds(old); validate_creds(old);
*new = *old; *new = *old;
atomic_set(&new->usage, 1);
set_cred_subscribers(new, 0);
get_uid(new->user); get_uid(new->user);
get_group_info(new->group_info); get_group_info(new->group_info);
@@ -674,8 +676,6 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
if (security_prepare_creds(new, old, GFP_KERNEL) < 0) if (security_prepare_creds(new, old, GFP_KERNEL) < 0)
goto error; goto error;
atomic_set(&new->usage, 1);
set_cred_subscribers(new, 0);
put_cred(old); put_cred(old);
validate_creds(new); validate_creds(new);
return new; return new;