Commit 04ec93fe authored Feb 06, 2009 by Li Zefan Committed by Linus Torvalds Feb 06, 2009

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 f1752eec).

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>

parent b2a740aa

kernel/fork.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;