From: Tetsuo Handa <[email protected]> ------------------- 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 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 <[email protected]> Signed-off-by: David Howells <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- fs/file_table.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/file_table.c b/fs/file_table.c index 32d12b7..d4be17f 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -123,13 +123,13 @@ 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 */ -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
