[3.16.y-ckt stable] Patch "path_openat(): fix double fput()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    path_openat(): fix double fput()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bedf03d0b88db4de0b66a1ef81df4faec7a0ceb4 Mon Sep 17 00:00:00 2001
From: Al Viro <viro at zeniv.linux.org.uk>
Date: Fri, 8 May 2015 22:53:15 -0400
Subject: path_openat(): fix double fput()

commit f15133df088ecadd141ea1907f2c96df67c729f0 upstream.

path_openat() jumps to the wrong place after do_tmpfile() - it has
already done path_cleanup() (as part of path_lookupat() called by
do_tmpfile()), so doing that again can lead to double fput().

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
[ luis: backported to 3.16:
  - adjusted context as 3.16 doesn't have path_cleanup() helper,
    introduced by 893b7775a70e ("fs/namei.c: new helper (path_cleanup())") ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/namei.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/namei.c b/fs/namei.c
index 19ac9c89dbab..15fc3f5a5007 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3194,7 +3194,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,

 	if (unlikely(file->f_flags & __O_TMPFILE)) {
 		error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened);
-		goto out;
+		goto out2;
 	}

 	error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base);
@@ -3232,6 +3232,7 @@ out:
 		path_put(&nd->root);
 	if (base)
 		fput(base);
+out2:
 	if (!(opened & FILE_OPENED)) {
 		BUG_ON(!error);
 		put_filp(file);