[PATCH 4.4 095/190] hdlcdrv: Fix divide by zero in hdlcdrv_ioctl

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Firo Yang 


[ Upstream commit fb3ce90b7d7761b6f7f28f0ff5c456ef6b5229a1 ]

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 
Signed-off-by: Firo Yang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/hamradio/hdlcdrv.c |2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -574,6 +574,8 @@ static int hdlcdrv_ioctl(struct net_devi
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;

[PATCH 4.4 095/190] hdlcdrv: Fix divide by zero in hdlcdrv_ioctl

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

--

From: Firo Yang 


[ Upstream commit fb3ce90b7d7761b6f7f28f0ff5c456ef6b5229a1 ]

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 
Signed-off-by: Firo Yang 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
---
 drivers/net/hamradio/hdlcdrv.c |2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -574,6 +574,8 @@ static int hdlcdrv_ioctl(struct net_devi
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;