| Message ID | 20170313124727.4681-1-petr.vorel@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, 2017-03-13 at 13:47 +0100, Petr Vorel wrote: > commit 7489bdadb7d1 (r8152: check rx after napi is enabled) causes null > pointer dereference when using device as under root: > > # rmmod r8152 # or lsusb -v > NOHZ: local_softirq_pending 08 > BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > IP: r8152_poll+0x125/0x570 [r8152] > PGD 89b4cf067 > PUD 898ff2067 > PMD 0 > Oops: 0002 [#1] PREEMPT SMP > > Signed-off-by: Petr Vorel <petr.vorel@gmail.com> > --- > NOTE: This is just a workaround, I suppose, there is better way how to fix that > (which allows keeping scheduling the napi for rx after napi_enable()). > --- > drivers/net/usb/r8152.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c > index 986243c932cc..79c665a89a47 100644 > --- a/drivers/net/usb/r8152.c > +++ b/drivers/net/usb/r8152.c > @@ -3703,8 +3703,6 @@ static int rtl8152_resume(struct usb_interface *intf) > napi_enable(&tp->napi); > clear_bit(SELECTIVE_SUSPEND, &tp->flags); > smp_mb__after_atomic(); > - if (!list_empty(&tp->rx_done)) > - napi_schedule(&tp->napi); > } else { > tp->rtl_ops.up(tp); > netif_carrier_off(tp->netdev); The proper work around is to enclose the napi_schedule() in a local_bh_enable()/local_bh_disable() pair.
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 986243c932cc..79c665a89a47 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c @@ -3703,8 +3703,6 @@ static int rtl8152_resume(struct usb_interface *intf) napi_enable(&tp->napi); clear_bit(SELECTIVE_SUSPEND, &tp->flags); smp_mb__after_atomic(); - if (!list_empty(&tp->rx_done)) - napi_schedule(&tp->napi); } else { tp->rtl_ops.up(tp); netif_carrier_off(tp->netdev);
commit 7489bdadb7d1 (r8152: check rx after napi is enabled) causes null pointer dereference when using device as under root: # rmmod r8152 # or lsusb -v NOHZ: local_softirq_pending 08 BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: r8152_poll+0x125/0x570 [r8152] PGD 89b4cf067 PUD 898ff2067 PMD 0 Oops: 0002 [#1] PREEMPT SMP Signed-off-by: Petr Vorel <petr.vorel@gmail.com> --- NOTE: This is just a workaround, I suppose, there is better way how to fix that (which allows keeping scheduling the napi for rx after napi_enable()). --- drivers/net/usb/r8152.c | 2 -- 1 file changed, 2 deletions(-)