[3.8.y.z extended stable] Patch "drivers/net/hamradio: Integer overflow in hdlcdrv_ioctl()" has been added to staging queue

[Kamal Mostafa]

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

    drivers/net/hamradio: Integer overflow in hdlcdrv_ioctl()

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.16.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 66a884eaac5e724d12d9064fd3642f6f4f6e6909 Mon Sep 17 00:00:00 2001
From: Wenliang Fan <fanwlexca at gmail.com>
Date: Tue, 17 Dec 2013 11:25:28 +0800
Subject: drivers/net/hamradio: Integer overflow in hdlcdrv_ioctl()

[ Upstream commit e9db5c21d3646a6454fcd04938dd215ac3ab620a ]

The local variable 'bi' comes from userspace. If userspace passed a
large number to 'bi.data.calibrate', there would be an integer overflow
in the following line:
	s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;

Signed-off-by: Wenliang Fan <fanwlexca at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/hamradio/hdlcdrv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index a4a3516..3b3a7e0 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -571,6 +571,8 @@ static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	case HDLCDRVCTL_CALIBRATE:
 		if(!capable(CAP_SYS_RAWIO))
 			return -EPERM;
+		if (bi.data.calibrate > INT_MAX / s->par.bitrate)
+			return -EINVAL;
 		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 		return 0;

--
1.8.3.2