Messages in this thread Patch in this message | | | Date | Tue, 22 Feb 2011 14:17:03 -0800 | From | Greg KH <> | Subject | [24/70] CRED: Fix kernel panic upon security_file_alloc() failure. |
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2.6.37-stable review patch. If anyone has any objections, please let us know.
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From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
commit 78d2978874e4e10e97dfd4fd79db45bdc0748550 upstream.
In get_empty_filp() since 2.6.29, file_free(f) is called with f->f_cred == NULL when security_file_alloc() returned an error. As a result, kernel will panic() due to put_cred(NULL) call within RCU callback.
Fix this bug by assigning f->f_cred before calling security_file_alloc().
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>
--- fs/file_table.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/file_table.c +++ b/fs/file_table.c @@ -125,13 +125,13 @@ struct file *get_empty_filp(void) goto fail; percpu_counter_inc(&nr_files); + f->f_cred = get_cred(cred); if (security_file_alloc(f)) goto fail_sec; INIT_LIST_HEAD(&f->f_u.fu_list); atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); - f->f_cred = get_cred(cred); spin_lock_init(&f->f_lock); eventpoll_init_file(f); /* f->f_version: 0 */
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