* [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
@ 2017-03-13 12:47 Petr Vorel
2017-03-13 13:18 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Petr Vorel @ 2017-03-13 12:47 UTC (permalink / raw)
To: netdev; +Cc: Petr Vorel, hayeswang, davem
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);
--
2.12.0
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 12:47 [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll Petr Vorel
@ 2017-03-13 13:18 ` Eric Dumazet
2017-03-13 13:19 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2017-03-13 13:18 UTC (permalink / raw)
To: Petr Vorel; +Cc: netdev, hayeswang, davem
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.
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 13:18 ` Eric Dumazet
@ 2017-03-13 13:19 ` Eric Dumazet
2017-03-13 15:37 ` Petr Vorel
0 siblings, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2017-03-13 13:19 UTC (permalink / raw)
To: Petr Vorel; +Cc: netdev, hayeswang, davem
On Mon, 2017-03-13 at 06:18 -0700, Eric Dumazet wrote:
> 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.
Something like :
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 986243c932ccd6fe19c592805c1c63274f5e5555..b6bb1720c383946ea6142ec2f79f5b7a69031d7f 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -3703,8 +3703,10 @@ static int rtl8152_resume(struct usb_interface *intf)
napi_enable(&tp->napi);
clear_bit(SELECTIVE_SUSPEND, &tp->flags);
smp_mb__after_atomic();
+ local_bh_disable();
if (!list_empty(&tp->rx_done))
napi_schedule(&tp->napi);
+ local_bh_enable();
} else {
tp->rtl_ops.up(tp);
netif_carrier_off(tp->netdev);
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 13:19 ` Eric Dumazet
@ 2017-03-13 15:37 ` Petr Vorel
2017-03-13 15:44 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Petr Vorel @ 2017-03-13 15:37 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev, hayeswang, davem
Hi Eric,
> > The proper work around is to enclose the napi_schedule() in a
> > local_bh_enable()/local_bh_disable() pair.
> Something like :
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -3703,8 +3703,10 @@ static int rtl8152_resume(struct usb_interface *intf)
> napi_enable(&tp->napi);
> clear_bit(SELECTIVE_SUSPEND, &tp->flags);
> smp_mb__after_atomic();
> + local_bh_disable();
> if (!list_empty(&tp->rx_done))
> napi_schedule(&tp->napi);
> + local_bh_enable();
Unfortunately this doesn't work. Code in r8152.c doesn't use local_bh_enable()/local_bh_disable(). I tried to lock it with spin_lock_bh()/spin_unlock_bh() and with mutex_lock()/mutex_unlock() but neither work.
Kind regards,
Petr
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 15:37 ` Petr Vorel
@ 2017-03-13 15:44 ` Eric Dumazet
2017-03-13 15:46 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2017-03-13 15:44 UTC (permalink / raw)
To: Petr Vorel; +Cc: netdev, hayeswang, davem
On Mon, 2017-03-13 at 16:37 +0100, Petr Vorel wrote:
> Hi Eric,
>
> > > The proper work around is to enclose the napi_schedule() in a
> > > local_bh_enable()/local_bh_disable() pair.
>
> > Something like :
> > --- a/drivers/net/usb/r8152.c
> > +++ b/drivers/net/usb/r8152.c
> > @@ -3703,8 +3703,10 @@ static int rtl8152_resume(struct usb_interface *intf)
> > napi_enable(&tp->napi);
> > clear_bit(SELECTIVE_SUSPEND, &tp->flags);
> > smp_mb__after_atomic();
> > + local_bh_disable();
> > if (!list_empty(&tp->rx_done))
> > napi_schedule(&tp->napi);
> > + local_bh_enable();
>
> Unfortunately this doesn't work. Code in r8152.c doesn't use
> local_bh_enable()/local_bh_disable(). I tried to lock it with
> spin_lock_bh()/spin_unlock_bh() and with mutex_lock()/mutex_unlock()
> but neither work.
The local_bh_disable() / local_bh_enable() definitely is the right
answer to the issue you described.
It does not matter what code in r8152.c currently does.
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=8cf699ec849f4ca1413cea01289bd7d37dbcc626
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 15:44 ` Eric Dumazet
@ 2017-03-13 15:46 ` Eric Dumazet
2017-03-13 21:57 ` Petr Vorel
0 siblings, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2017-03-13 15:46 UTC (permalink / raw)
To: Petr Vorel; +Cc: netdev, hayeswang, davem
On Mon, 2017-03-13 at 08:44 -0700, Eric Dumazet wrote:
> On Mon, 2017-03-13 at 16:37 +0100, Petr Vorel wrote:
> > Hi Eric,
> >
> > > > The proper work around is to enclose the napi_schedule() in a
> > > > local_bh_enable()/local_bh_disable() pair.
> >
> > > Something like :
> > > --- a/drivers/net/usb/r8152.c
> > > +++ b/drivers/net/usb/r8152.c
> > > @@ -3703,8 +3703,10 @@ static int rtl8152_resume(struct usb_interface *intf)
> > > napi_enable(&tp->napi);
> > > clear_bit(SELECTIVE_SUSPEND, &tp->flags);
> > > smp_mb__after_atomic();
> > > + local_bh_disable();
> > > if (!list_empty(&tp->rx_done))
> > > napi_schedule(&tp->napi);
> > > + local_bh_enable();
> >
> > Unfortunately this doesn't work. Code in r8152.c doesn't use
> > local_bh_enable()/local_bh_disable(). I tried to lock it with
> > spin_lock_bh()/spin_unlock_bh() and with mutex_lock()/mutex_unlock()
> > but neither work.
>
> The local_bh_disable() / local_bh_enable() definitely is the right
> answer to the issue you described.
>
> It does not matter what code in r8152.c currently does.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=8cf699ec849f4ca1413cea01289bd7d37dbcc626
You also have to protect other napi_schedule(), like the ones in
rtl_work_func_t() or rtl8152_post_reset()
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll
2017-03-13 15:46 ` Eric Dumazet
@ 2017-03-13 21:57 ` Petr Vorel
2017-03-14 6:15 ` [PATCH net] r8152: fix the list rx_done may be used without initialization Hayes Wang
0 siblings, 1 reply; 11+ messages in thread
From: Petr Vorel @ 2017-03-13 21:57 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev, hayeswang, davem
> > > Unfortunately this doesn't work. Code in r8152.c doesn't use
> > > local_bh_enable()/local_bh_disable(). I tried to lock it with
> > > spin_lock_bh()/spin_unlock_bh() and with mutex_lock()/mutex_unlock()
> > > but neither work.
> > The local_bh_disable() / local_bh_enable() definitely is the right
> > answer to the issue you described.
> > It does not matter what code in r8152.c currently does.
> > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=8cf699ec849f4ca1413cea01289bd7d37dbcc626
> You also have to protect other napi_schedule(), like the ones in
> rtl_work_func_t() or rtl8152_post_reset()
I've tested that before :-). I'll be more precise what "not working" means: it fixes
invalid pointer issue, but kernel crashes for different reason:
...
Call Trace:
<IRQ>
net_rx_action+0x23c/0x3f0
__do_softirq+0x104/0x2e1
? usb_runtime_suspend+0x70/0x70 [usbcore]
do_softirq_own_stack+8x1c/0x30
</IRQ>
do_softirq.part.18+0x41/0x50
__local_bh_enable_ip+0x88/0xa0
rtl8152_resume+0xe2/0x1a0 [r8152]
usb_resume_interface.isra.60x99/0xf0 [usbcore]
usb_resume_both+0x6a/0x130 [usbcore]
__rpm_callback+0xb9/0x1f0
rpm_callback+Ox5f/0x80
? usb_runtime_suspend+0x70/0x70 [usbcore]
usb_resume+0x495/0x6b0
? update_load_avg+Ox79/0x520
? update_load_avg+Ox79/0x520
? refcount_dec_and_test+0x11/0x20
__pm_runtime_resume+0x3f/0x60
usb_autoresume_device+0x23/0x50 [usbcore]
usb_dev_open+0xe7/0x250 [usbcore]
chrdev_open+0xa1/0x200
do_dentry_open+0x20a/0x2f0
? cdev_put+0x30/0x30
vfs_open+0x4c/0x70
? may_open+0x9b/0x100
path_openat+0x5ec/0x1430
do_filp_open+0x7e/0xe0
? __vfs_write+0x28/0x140
? __alloc_fd+0xb2/0x160
do_sys_open+0x123/0x200
SyS_open+0x1e/0x20
entry_SYSCALL_64_fastpath+0x1e/0xad
...
Kernel panic - not syncing: Fatal exception in interrupt
...
Patch: http://pastebin.com/Uejjc0Bh (I don't post patch here, as it's not working).
Kind regards,
Petr
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH net] r8152: fix the list rx_done may be used without initialization
2017-03-13 21:57 ` Petr Vorel
@ 2017-03-14 6:15 ` Hayes Wang
2017-03-14 8:53 ` Petr Vorel
2017-03-21 21:37 ` David Miller
0 siblings, 2 replies; 11+ messages in thread
From: Hayes Wang @ 2017-03-14 6:15 UTC (permalink / raw)
To: netdev, petr.vorel; +Cc: nic_swsd, linux-kernel, linux-usb, Hayes Wang
The list rx_done would be initialized when the linking on occurs.
Therefore, if a napi is scheduled without any linking on before,
the following kernel panic would happen.
BUG: unable to handle kernel NULL pointer dereference at 000000000000008
IP: [<ffffffffc085efde>] r8152_poll+0xe1e/0x1210 [r8152]
PGD 0
Oops: 0002 [#1] SMP
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
---
drivers/net/usb/r8152.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 986243c..bb3eedd 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1362,6 +1362,7 @@ static int alloc_all_mem(struct r8152 *tp)
spin_lock_init(&tp->rx_lock);
spin_lock_init(&tp->tx_lock);
INIT_LIST_HEAD(&tp->tx_free);
+ INIT_LIST_HEAD(&tp->rx_done);
skb_queue_head_init(&tp->tx_queue);
skb_queue_head_init(&tp->rx_queue);
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH net] r8152: fix the list rx_done may be used without initialization
2017-03-14 6:15 ` [PATCH net] r8152: fix the list rx_done may be used without initialization Hayes Wang
@ 2017-03-14 8:53 ` Petr Vorel
2017-03-14 9:17 ` Hayes Wang
2017-03-21 21:37 ` David Miller
1 sibling, 1 reply; 11+ messages in thread
From: Petr Vorel @ 2017-03-14 8:53 UTC (permalink / raw)
To: Hayes Wang; +Cc: netdev
Hi Hayes,
> The list rx_done would be initialized when the linking on occurs.
> Therefore, if a napi is scheduled without any linking on before,
> the following kernel panic would happen.
> BUG: unable to handle kernel NULL pointer dereference at 000000000000008
> IP: [<ffffffffc085efde>] r8152_poll+0xe1e/0x1210 [r8152]
> PGD 0
> Oops: 0002 [#1] SMP
thanks for fixing!
Kind regards,
Petr
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH net] r8152: fix the list rx_done may be used without initialization
2017-03-14 6:15 ` [PATCH net] r8152: fix the list rx_done may be used without initialization Hayes Wang
2017-03-14 8:53 ` Petr Vorel
@ 2017-03-21 21:37 ` David Miller
1 sibling, 0 replies; 11+ messages in thread
From: David Miller @ 2017-03-21 21:37 UTC (permalink / raw)
To: hayeswang; +Cc: netdev, petr.vorel, nic_swsd, linux-kernel, linux-usb
From: Hayes Wang <hayeswang@realtek.com>
Date: Tue, 14 Mar 2017 14:15:20 +0800
> The list rx_done would be initialized when the linking on occurs.
> Therefore, if a napi is scheduled without any linking on before,
> the following kernel panic would happen.
>
> BUG: unable to handle kernel NULL pointer dereference at 000000000000008
> IP: [<ffffffffc085efde>] r8152_poll+0xe1e/0x1210 [r8152]
> PGD 0
> Oops: 0002 [#1] SMP
>
> Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Applied.
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2017-03-21 21:46 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-03-13 12:47 [PATCH 1/1] r8152: fix NULL pointer dereference in r8152_poll Petr Vorel
2017-03-13 13:18 ` Eric Dumazet
2017-03-13 13:19 ` Eric Dumazet
2017-03-13 15:37 ` Petr Vorel
2017-03-13 15:44 ` Eric Dumazet
2017-03-13 15:46 ` Eric Dumazet
2017-03-13 21:57 ` Petr Vorel
2017-03-14 6:15 ` [PATCH net] r8152: fix the list rx_done may be used without initialization Hayes Wang
2017-03-14 8:53 ` Petr Vorel
2017-03-14 9:17 ` Hayes Wang
2017-03-21 21:37 ` David Miller
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