From mboxrd@z Thu Jan 1 00:00:00 1970 From: Firo Yang Subject: [PATCH] hdlcdrv: fix divide error bug if bitrate is 0 Date: Wed, 17 May 2017 20:35:49 +0800 Message-ID: <20170517123549.22659-1-firogm@gmail.com> Cc: davem@davemloft.net, gregkh@linuxfoundation.org, linux-hams@vger.kernel.org, netdev@vger.kernel.org, dvyukov@google.com, syzkaller@googlegroups.com, Firo Yang To: t.sailer@alumni.ethz.ch Return-path: Received: from mail-pf0-f194.google.com ([209.85.192.194]:32784 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751991AbdEQMgJ (ORCPT ); Wed, 17 May 2017 08:36:09 -0400 Sender: netdev-owner@vger.kernel.org List-ID: The divisor s->par.bitrate will always be 0 until initialized by ndo_open() and hdlcdrv_open(). In order to fix this divide zero error, check whether the netdevice was opened by ndo_open() before performing divide. Reported-by: Dmitry Vyukov Signed-off-by: Firo Yang --- drivers/net/hamradio/hdlcdrv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c index 8c3633c..3c783fd 100644 --- a/drivers/net/hamradio/hdlcdrv.c +++ b/drivers/net/hamradio/hdlcdrv.c @@ -574,7 +574,7 @@ static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) break; case HDLCDRVCTL_CALIBRATE: - if(!capable(CAP_SYS_RAWIO)) + if (!capable(CAP_SYS_RAWIO) || !netif_running(dev)) return -EPERM; if (bi.data.calibrate > INT_MAX / s->par.bitrate) return -EINVAL; -- 2.9.4