From: Alexey Dobriyan <adobriyan@openvz.org>

crap, Pavel reminded that get_proc_task() can return NULL.

Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/base.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff -puN fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid-update fs/proc/base.c
--- a/fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid-update
+++ a/fs/proc/base.c
@@ -1461,9 +1461,11 @@ static int proc_fd_permission(struct ino
 	if (rv == 0)
 		return 0;
 	tsk = get_proc_task(inode);
-	if (tsk == current)
-		rv = 0;
-	put_task_struct(tsk);
+	if (tsk) {
+		if (tsk == current)
+			rv = 0;
+		put_task_struct(tsk);
+	}
 	return rv;
 }
 
_