On Wed, May 17, 2017 at 02:59:39PM +0200, walter harms wrote:
>
>
>Am 17.05.2017 14:35, schrieb Firo Yang:
>> 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 <dvyu...@google.com>
>> Signed-off-by: Firo Yang <fir...@gmail.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..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.
I think 0 is not valid value for bitrate, so we should check it in
other places, like what ser12_open() did:
429 if (bc->baud < 300 || bc->baud > 4800) {
430 printk(KERN_INFO "baycom_ser_fdx: invalid baudrate "
431 "(300...4800)\n");
432 return -EINVAL;
433 }
...
440 bc->hdrv.par.bitrate = bc->baud;
>
>Also perhaps !netif_running(dev) should better return ENODEV.
However, the 'dev' truly exists in this circumstance.
Thanks,
Firo
>
>
>just my 2 cents,
>re,
> wh
>
