Re: [PATCH] hdlcdrv: fix divide error bug if bitrate is 0
From: walter harms <hidden>
Date: 2017-05-17 12:59:39
Also in:
linux-hams
Am 17.05.2017 14:35, schrieb Firo Yang:
quoted hunk ↗ jump to hunk
The divisor s->par.bitrate will always be 0 until initialized by ndo_open() and hdlcdrv_open(). In order to fix this divide zero error, check whether the netdevice was opened by ndo_open() before performing divide. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Firo Yang <redacted> --- 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..3c783fd 100644 --- a/drivers/net/hamradio/hdlcdrv.c +++ b/drivers/net/hamradio/hdlcdrv.c@@ -574,7 +574,7 @@ static int hdlcdrv_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) break; case HDLCDRVCTL_CALIBRATE: - if(!capable(CAP_SYS_RAWIO)) + if (!capable(CAP_SYS_RAWIO) || !netif_running(dev)) return -EPERM; if (bi.data.calibrate > INT_MAX / s->par.bitrate) return -EINVAL;
I would still check for s->par.bitrate > 0 later changes may affect the setting of it and it is much more obvious. Also perhaps !netif_running(dev) should better return ENODEV. just my 2 cents, re, wh