fork.c: fix NULL pointer dereference when nr_threads == threads-max

I happened to forked lots of processes, and hit NULL pointer dereference.
It is because in copy_process() after checking max_threads, 0 is returned
but not -EAGAIN.

The bug is introduced by "CRED: Detach the credentials from task_struct"
(commit f1752eec61).

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Li Zefan 2009-02-06 08:17:19 +00:00 committed by Linus Torvalds
parent b2a740aab8
commit 04ec93fe9b
1 changed files with 1 additions and 0 deletions

View File

@ -1005,6 +1005,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
* triggers too late. This doesn't hurt, the check is only there
* to stop root fork bombs.
*/
retval = -EAGAIN;
if (nr_threads >= max_threads)
goto bad_fork_cleanup_count;