From: Alexey Dobriyan <adobriyan@openvz.org>

Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/base.c |    9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff -puN fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid-update-2 fs/proc/base.c
--- a/fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid-update-2
+++ a/fs/proc/base.c
@@ -1454,18 +1454,13 @@ static struct file_operations proc_fd_op
 static int proc_fd_permission(struct inode *inode, int mask,
 				struct nameidata *nd)
 {
-	struct task_struct *tsk;
 	int rv;
 
 	rv = generic_permission(inode, mask, NULL);
 	if (rv == 0)
 		return 0;
-	tsk = get_proc_task(inode);
-	if (tsk) {
-		if (tsk == current)
-			rv = 0;
-		put_task_struct(tsk);
-	}
+	if (task_pid(current) == proc_pid(inode))
+		rv = 0;
 	return rv;
 }
 
_