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 f1752ee). Signed-off-by: Li Zefan <[email protected]> Signed-off-by: David Howells <[email protected]> Acked-by: James Morris <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
chewitt · Feb 6, 2009 · 04ec93f · 04ec93f
1 parent b2a740a
commit 04ec93f
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/kernel/fork.c b/kernel/fork.c
@@ -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;