This is a note to let you know that I've just added the patch titled hdlcdrv: Fix divide by zero in hdlcdrv_ioctl to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hdlcdrv-fix-divide-by-zero-in-hdlcdrv_ioctl.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Apr 10 13:58:07 CEST 2018 From: Firo Yang <firogm@xxxxxxxxx> Date: Fri, 26 May 2017 22:37:38 +0800 Subject: hdlcdrv: Fix divide by zero in hdlcdrv_ioctl From: Firo Yang <firogm@xxxxxxxxx> [ 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@xxxxxxxxxx> Signed-off-by: Firo Yang <firogm@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/hamradio/hdlcdrv.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/hamradio/hdlcdrv.c +++ b/drivers/net/hamradio/hdlcdrv.c @@ -571,6 +571,8 @@ 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; Patches currently in stable-queue which might be from firogm@xxxxxxxxx are queue-3.18/hdlcdrv-fix-divide-by-zero-in-hdlcdrv_ioctl.patch