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

[Luis Henriques]

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-3.11.y-queue branch of the 3.11.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-3.11.y-queue

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

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e5a468ad24d5589456e254ddbda8e1a209a51666 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()

commit e9db5c21d3646a6454fcd04938dd215ac3ab620a upstream.

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: Luis Henriques <luis.henriques 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 3169252..5d78c1d 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