From: Firo Yang <firogm@gmail•com>
To: davem@davemloft•net, alan@linux•intel.com
Cc: t.sailer@alumni•ethz.ch, wharms@bfs•de, andreyknvl@google•com,
linux-hams@vger•kernel.org, gregkh@linuxfoundation•org,
netdev@vger•kernel.org, thomas@osterried•de,
javier@osg•samsung.com, dhowells@redhat•com,
geliangtang@gmail•com, linux-kernel@vger•kernel.org,
Firo Yang <firogm@gmail•com>
Subject: [PATCH v3] hdlcdrv: Fix divide by zero in hdlcdrv_ioctl
Date: Fri, 26 May 2017 22:37:38 +0800 [thread overview]
Message-ID: <20170526143738.26749-1-firogm@gmail.com> (raw)
In-Reply-To: <CAAeHK+ya2sAtLmJ0VyP6e=13OXUw98dp1WdRFU=o5+xGFGPtbQ@mail.gmail.com>
syszkaller fuzzer triggered a divide by zero, when set calibration
through ioctl().
To fix it, test 'bitrate' if it is negative or 0, just return -EINVAL.
Reported-by: Andrey Konovalov <andreyknvl@google•com>
Signed-off-by: Firo Yang <firogm@gmail•com>
---
v2->v3:
Just fix divide error and remove netif_running() test.
Refine the testing code as David Miller suggested.
v1->v2:
Change Reported-by to Andrey Konovalov.
Send it to original report thread.
v0->v1:
Reviewed by walter harms <wharms@bfs•de>.
Return ENODEV instead of EPERM if !netif_running(dev)
Check if s->par.bitrate > 0.
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 8c3633c..97e3bc6 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -576,6 +576,8 @@ static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
case HDLCDRVCTL_CALIBRATE:
if(!capable(CAP_SYS_RAWIO))
return -EPERM;
+ if (s->par.bitrate <= 0)
+ return -EINVAL;
if (bi.data.calibrate > INT_MAX / s->par.bitrate)
return -EINVAL;
s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
--
2.9.4
next prev parent reply other threads:[~2017-05-26 14:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-16 15:05 drivers/net/hamradio: divide error in hdlcdrv_ioctl Andrey Konovalov
2017-05-16 15:05 ` Andrey Konovalov
2017-05-17 20:07 ` Alan Cox
2017-05-19 0:29 ` Andrey Konovalov
2017-05-19 13:21 ` [PATCH v2] hdlcdrv: fix divide error bug if bitrate is 0 Firo Yang
2017-05-19 21:41 ` David Miller
2017-05-26 14:37 ` Firo Yang [this message]
2017-05-27 22:45 ` [PATCH v3] hdlcdrv: Fix divide by zero in hdlcdrv_ioctl David Miller
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