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From: Alan Cox <alan@llwyncelyn.cymru>
To: mchehab@kernel.org, linux-media@vger.kernel.org
Subject: [PATCH 05/12] hdlcdrv: Fix division by zero when bitrate is unset
Date: Fri, 26 May 2017 16:26:42 +0100	[thread overview]
Message-ID: <149581238775.17406.4594436624734437821.stgit@builder> (raw)
In-Reply-To: <149581234670.17406.8086980349538517529.stgit@builder>

The code attempts to check for out of range calibration. What it forgets to do
is check for the 0 bitrate case. As a result the range check itself oopses the
kernel.

Found by Andrey Konovalov using Syzkaller.

Signed-off-by: Alan Cox <alan@linux.intel.com>
---
 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..9f34a48 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -576,7 +576,7 @@ 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)
+		if (!s->par.bitrate || bi.data.calibrate > INT_MAX / s->par.bitrate)
 			return -EINVAL;
 		s->hdlctx.calibrate = bi.data.calibrate * s->par.bitrate / 16;
 		return 0;

      parent reply	other threads:[~2017-05-26 15:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-26 15:25 [PATCH 01/12] atompisp: HAS_BL is never defined so lose it Alan Cox
2017-05-26 15:25 ` [PATCH 02/12] atomisp: remove NUM_OF_BLS Alan Cox
2017-05-26 15:26 ` [PATCH 03/12] atomisp2: remove HRT_UNSCHED Alan Cox
2017-05-26 15:26 ` [PATCH 04/12] atomisp2: tidy up confused ifdefs Alan Cox
2017-05-26 15:26 ` Alan Cox [this message]

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