[3.16.y-ckt stable] Patch "macvtap: fix TUNSETSNDBUF values > 64k" has been added to staging queue

[Kamal Mostafa]

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

    macvtap: fix TUNSETSNDBUF values > 64k

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 3.19.8-ckt9.

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.
-Kamal

------

>From 6613d1070efb7301fd591f657b3d26fc291b6b1a Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst at redhat.com>
Date: Fri, 18 Sep 2015 13:41:09 +0300
Subject: macvtap: fix TUNSETSNDBUF values > 64k

commit 3ea79249e81e5ed051f2e6480cbde896d99046e8 upstream.

Upon TUNSETSNDBUF,  macvtap reads the requested sndbuf size into
a local variable u.
commit 39ec7de7092b ("macvtap: fix uninitialized access on
TUNSETIFF") changed its type to u16 (which is the right thing to
do for all other macvtap ioctls), breaking all values > 64k.

The value of TUNSETSNDBUF is actually a signed 32 bit integer, so
the right thing to do is to read it into an int.

Cc: David S. Miller <davem at davemloft.net>
Fixes: 39ec7de7092b ("macvtap: fix uninitialized access on TUNSETIFF")
Reported-by: Mark A. Peloquin
Bisected-by: Matthew Rosato <mjrosato at linux.vnet.ibm.com>
Reported-by: Christian Borntraeger <borntraeger at de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Tested-by:  Matthew Rosato <mjrosato at linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger at de.ibm.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/macvtap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 4d050ee..84e835e 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -1054,10 +1054,10 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
 		return 0;

 	case TUNSETSNDBUF:
-		if (get_user(u, up))
+		if (get_user(s, sp))
 			return -EFAULT;

-		q->sk.sk_sndbuf = u;
+		q->sk.sk_sndbuf = s;
 		return 0;

 	case TUNGETVNETHDRSZ:
--
1.9.1