| From foo@baz Mon Apr 9 17:09:24 CEST 2018 |
| From: Firo Yang <firogm@gmail.com> |
| Date: Fri, 26 May 2017 22:37:38 +0800 |
| Subject: hdlcdrv: Fix divide by zero in hdlcdrv_ioctl |
| |
| From: Firo Yang <firogm@gmail.com> |
| |
| |
| [ 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 <andreyknvl@google.com> |
| Signed-off-by: Firo Yang <firogm@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/hamradio/hdlcdrv.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/drivers/net/hamradio/hdlcdrv.c |
| +++ b/drivers/net/hamradio/hdlcdrv.c |
| @@ -576,6 +576,8 @@ 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; |
