From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wenliang Fan Subject: [PATCH] drivers/net/hamradio: Integer overflow in hdlcdrv_ioctl() Date: Tue, 17 Dec 2013 11:25:28 +0800 Message-ID: <1387250728-10795-1-git-send-email-fanwlexca@gmail.com> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Wenliang Fan To: davem@davemloft.net, michael.opdenacker@free-electrons.com, gaofeng@cn.fujitsu.com, akpm@linux-foundation.org, t.sailer@alumni.ethz.ch Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- 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; -- 1.8.5.rc1.28.g7061504