| Message ID | 20170517123549.22659-1-firogm@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
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 <dvyukov@google.com> > Signed-off-by: Firo Yang <firogm@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. Also perhaps !netif_running(dev) should better return ENODEV. just my 2 cents, re, wh
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 <dvyukov@google.com> >> Signed-off-by: Firo Yang <firogm@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 >
Am 17.05.2017 15:42, schrieb Firo Yang: > 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 <dvyukov@google.com> >>> Signed-off-by: Firo Yang <firogm@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; I do not want to say you change is not valid but i have learned that it is better to have an obvious check that to rely on hidden knowledge. > >> >> Also perhaps !netif_running(dev) should better return ENODEV. > > However, the 'dev' truly exists in this circumstance. > yes and i do not feel good with that but "no permission" will lead any enduser into a search for user rights. re, wh > Thanks, > Firo > >> >> >> just my 2 cents, >> re, >> wh >>
On Wed, May 17, 2017 at 06:08:11PM +0200, walter harms wrote: > > >Am 17.05.2017 15:42, schrieb Firo Yang: >> 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 <dvyukov@google.com> >>>> Signed-off-by: Firo Yang <firogm@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; > > >I do not want to say you change is not valid but i have learned that it is better to >have an obvious check that to rely on hidden knowledge. I agree with this. > > >> >>> >>> Also perhaps !netif_running(dev) should better return ENODEV. >> >> However, the 'dev' truly exists in this circumstance. >> > >yes and i do not feel good with that but "no permission" will lead >any enduser into a search for user rights. Indeed, ENODEV is more informative to enduser. I will send a update patch. Thanks, Firo > > > >re, > wh > > >> Thanks, >> Firo >> >>> >>> >>> just my 2 cents, >>> re, >>> wh >>>
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;
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 <firogm@gmail.com> --- drivers/net/hamradio/hdlcdrv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)