Patch "NFSv4.x: hide array-bounds warning" has been added to the 4.4-stable tree

Patch "NFSv4.x: hide array-bounds warning" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    NFSv4.x: hide array-bounds warning

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsv4.x-hide-array-bounds-warning.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d55b352b01bc78fbc3d1bb650140668b87e58bf9 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 22 Nov 2016 21:50:52 +0100
Subject: NFSv4.x: hide array-bounds warning

From: Arnd Bergmann <arnd@arndb.de>

commit d55b352b01bc78fbc3d1bb650140668b87e58bf9 upstream.

A correct bugfix introduced a harmless warning that shows up with gcc-7:

fs/nfs/callback.c: In function 'nfs_callback_up':
fs/nfs/callback.c:214:14: error: array subscript is outside array bounds [-Werror=array-bounds]

What happens here is that the 'minorversion == 0' check tells the
compiler that we assume minorversion can be something other than 0,
but when CONFIG_NFS_V4_1 is disabled that would be invalid and
result in an out-of-bounds access.

The added check for IS_ENABLED(CONFIG_NFS_V4_1) tells gcc that this
really can't happen, which makes the code slightly smaller and also
avoids the warning.

The bugfix that introduced the warning is marked for stable backports,
we want this one backported to the same releases.

Fixes: 98b0f80c2396 ("NFSv4.x: Fix a refcount leak in nfs_callback_up_net")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/callback.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -261,7 +261,7 @@ static int nfs_callback_up_net(int minor
 	}
 
 	ret = -EPROTONOSUPPORT;
-	if (minorversion == 0)
+	if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
 		ret = nfs4_callback_up_net(serv, net);
 	else if (xprt->ops->bc_up)
 		ret = xprt->ops->bc_up(serv, net);


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-4.4/nfsv4.x-hide-array-bounds-warning.patch