kernel OOPS when releasing usb webcam (random)

kernel OOPS when releasing usb webcam (random)

[Tomas M.]

im getting the following null pointer dereference from time to time when 
releasing a usb camera.

maybe this trace is of assistance...please reply to my mail since im not 
subscribed.


thanks.

Tomas M.
---
BUG: unable to handle kernel NULL pointer dereference at 0000006c
IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]
*pde = 00000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: fuse arc4 rt73usb rt2x00usb rt2x00lib mac80211 
cfg80211 rfkill gspca_zc3xx gspca_main videodev joydev 
snd_hda_codec_si3054 sg 8139too snd_hda_codec_realtek firewire_ohci 
firewire_core mmc_core snd_hda_intel snd_hda_codec snd_hwdep snd_pcm 
snd_timer snd soundcore mii crc_itu_t snd_page_alloc iTCO_wdt 
iTCO_vendor_support i2c_i801 evdev psmouse thermal battery serio_raw ac 
cpufreq_ondemand acpi_cpufreq freq_table processor mperf usbhid hid ext3 
jbd mbcache sd_mod sr_mod cdrom pata_acpi uhci_hcd ata_piix ehci_hcd 
libata scsi_mod usbcore [last unloaded: sdhci]

Pid: 171, comm: khubd Not tainted 3.1.0-rc9 #66 Everex Systems, Inc. 
Everex StepNote Series/Everex StepNote Series
EIP: 0060:[<f90be6c2>] EFLAGS: 00010292 CPU: 0
EIP is at v4l2_device_release+0xa2/0xf0 [videodev]
EAX: 00000000 EBX: f5636004 ECX: 00000000 EDX: 00000000
ESI: f5636000 EDI: 00000000 EBP: f563600c ESP: f5627e38
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process khubd (pid: 171, ti=f5626000 task=f554dc00 task.ti=f5626000)
Stack:
  ef000480 c1433780 f5474b00 c12343f8 f54e7e1c 00000000 c114737a f563600c
  f5636028 c114605d f5636028 c1146020 f91512d4 00000000 c114737a f54e7e1c
  f54e7e00 f81623f4 f56d4000 f54e7e1c f91512d4 f56d4064 00000001 c12373b7
Call Trace:
  [<c12343f8>] ? device_release+0x18/0x80
  [<c114737a>] ? kref_put+0x2a/0x60
  [<c114605d>] ? kobject_release+0x3d/0xa0
  [<c1146020>] ? kobject_del+0x30/0x30
  [<c114737a>] ? kref_put+0x2a/0x60
  [<f81623f4>] ? usb_unbind_interface+0x34/0x130 [usbcore]
  [<c12373b7>] ? __device_release_driver+0x57/0xb0
  [<c123742d>] ? device_release_driver+0x1d/0x30
  [<c1236fc2>] ? bus_remove_device+0x72/0x90
  [<c12350bf>] ? device_del+0xdf/0x150
  [<f8160591>] ? usb_disable_device+0x81/0x180 [usbcore]
  [<f8159b3b>] ? usb_disconnect+0x8b/0x110 [usbcore]
  [<f815b76c>] ? hub_thread+0x97c/0x1180 [usbcore]
  [<c102d80b>] ? pick_next_task_fair+0x8b/0xe0
  [<c1052600>] ? abort_exclusive_wait+0x90/0x90
  [<f815adf0>] ? usb_remote_wakeup+0x40/0x40 [usbcore]
  [<c1052029>] ? kthread+0x69/0x70
  [<c1051fc0>] ? kthread_worker_fn+0x150/0x150
  [<c130d8be>] ? kernel_thread_helper+0x6/0xd
Code: 83 94 01 00 00 c7 83 60 01 00 00 00 00 00 00 0f b7 93 9c 01 00 00 
c1 e0 05 f0 0f b3 90 c0 e7 0c f9 b8 20 e1 0c f9 e8 4e cf 24 c8 <8b> 57 
6c 89 f0 85 d2 74 25 ff 93 c8 01 00 00 85 ff 74 21 89 f8
EIP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev] SS:ESP 
0068:f5627e38
CR2: 000000000000006c
---[ end trace 39522f0f1757c8f8 ]---

Re: kernel OOPS when releasing usb webcam (random)

[David Rientjes]

On Mon, 17 Oct 2011, Tomas M. wrote:

> im getting the following null pointer dereference from time to time when
> releasing a usb camera.
> 
> maybe this trace is of assistance...please reply to my mail since im not
> subscribed.
> 

I suspect this is happening in v4l2_device_unregister_subdev().  Adding 
Guennadi, Mauro, and linux-media.

> BUG: unable to handle kernel NULL pointer dereference at 0000006c
> IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]
> *pde = 00000000
> Oops: 0000 [#1] PREEMPT SMP
> Modules linked in: fuse arc4 rt73usb rt2x00usb rt2x00lib mac80211 cfg80211
> rfkill gspca_zc3xx gspca_main videodev joydev snd_hda_codec_si3054 sg 8139too
> snd_hda_codec_realtek firewire_ohci firewire_core mmc_core snd_hda_intel
> snd_hda_codec snd_hwdep snd_pcm snd_timer snd soundcore mii crc_itu_t
> snd_page_alloc iTCO_wdt iTCO_vendor_support i2c_i801 evdev psmouse thermal
> battery serio_raw ac cpufreq_ondemand acpi_cpufreq freq_table processor mperf
> usbhid hid ext3 jbd mbcache sd_mod sr_mod cdrom pata_acpi uhci_hcd ata_piix
> ehci_hcd libata scsi_mod usbcore [last unloaded: sdhci]
> 
> Pid: 171, comm: khubd Not tainted 3.1.0-rc9 #66 Everex Systems, Inc. Everex
> StepNote Series/Everex StepNote Series
> EIP: 0060:[<f90be6c2>] EFLAGS: 00010292 CPU: 0
> EIP is at v4l2_device_release+0xa2/0xf0 [videodev]
> EAX: 00000000 EBX: f5636004 ECX: 00000000 EDX: 00000000
> ESI: f5636000 EDI: 00000000 EBP: f563600c ESP: f5627e38
>  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
> Process khubd (pid: 171, ti=f5626000 task=f554dc00 task.ti=f5626000)
> Stack:
>  ef000480 c1433780 f5474b00 c12343f8 f54e7e1c 00000000 c114737a f563600c
>  f5636028 c114605d f5636028 c1146020 f91512d4 00000000 c114737a f54e7e1c
>  f54e7e00 f81623f4 f56d4000 f54e7e1c f91512d4 f56d4064 00000001 c12373b7
> Call Trace:
>  [<c12343f8>] ? device_release+0x18/0x80
>  [<c114737a>] ? kref_put+0x2a/0x60
>  [<c114605d>] ? kobject_release+0x3d/0xa0
>  [<c1146020>] ? kobject_del+0x30/0x30
>  [<c114737a>] ? kref_put+0x2a/0x60
>  [<f81623f4>] ? usb_unbind_interface+0x34/0x130 [usbcore]
>  [<c12373b7>] ? __device_release_driver+0x57/0xb0
>  [<c123742d>] ? device_release_driver+0x1d/0x30
>  [<c1236fc2>] ? bus_remove_device+0x72/0x90
>  [<c12350bf>] ? device_del+0xdf/0x150
>  [<f8160591>] ? usb_disable_device+0x81/0x180 [usbcore]
>  [<f8159b3b>] ? usb_disconnect+0x8b/0x110 [usbcore]
>  [<f815b76c>] ? hub_thread+0x97c/0x1180 [usbcore]
>  [<c102d80b>] ? pick_next_task_fair+0x8b/0xe0
>  [<c1052600>] ? abort_exclusive_wait+0x90/0x90
>  [<f815adf0>] ? usb_remote_wakeup+0x40/0x40 [usbcore]
>  [<c1052029>] ? kthread+0x69/0x70
>  [<c1051fc0>] ? kthread_worker_fn+0x150/0x150
>  [<c130d8be>] ? kernel_thread_helper+0x6/0xd
> Code: 83 94 01 00 00 c7 83 60 01 00 00 00 00 00 00 0f b7 93 9c 01 00 00 c1 e0
> 05 f0 0f b3 90 c0 e7 0c f9 b8 20 e1 0c f9 e8 4e cf 24 c8 <8b> 57 6c 89 f0 85
> d2 74 25 ff 93 c8 01 00 00 85 ff 74 21 89 f8
> EIP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev] SS:ESP
> 0068:f5627e38
> CR2: 000000000000006c
> ---[ end trace 39522f0f1757c8f8 ]---

[patch] Avoid NULL deref in v4l2_device_release (was Re: kernel OOPS when releasing usb webcam (random))

[Frederik Deweerdt]

[Adding relevant people to CCs]

Hi Tomas,

On Mon, Oct 17, 2011 at 07:48:34PM -0300, Tomas M. wrote:
> im getting the following null pointer dereference from time to time
> when releasing a usb camera.
> 
[...]
> BUG: unable to handle kernel NULL pointer dereference at 0000006c
> IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]
> *pde = 00000000
> Oops: 0000 [#1] PREEMPT SMP
> Modules linked in: fuse arc4 rt73usb rt2x00usb rt2x00lib mac80211
> cfg80211 rfkill gspca_zc3xx gspca_main videodev joydev
> snd_hda_codec_si3054 sg 8139too snd_hda_codec_realtek firewire_ohci
> firewire_core mmc_core snd_hda_intel snd_hda_codec snd_hwdep snd_pcm
> snd_timer snd soundcore mii crc_itu_t snd_page_alloc iTCO_wdt
> iTCO_vendor_support i2c_i801 evdev psmouse thermal battery serio_raw
> ac cpufreq_ondemand acpi_cpufreq freq_table processor mperf usbhid
> hid ext3 jbd mbcache sd_mod sr_mod cdrom pata_acpi uhci_hcd ata_piix
> ehci_hcd libata scsi_mod usbcore [last unloaded: sdhci]
> 
> Pid: 171, comm: khubd Not tainted 3.1.0-rc9 #66 Everex Systems, Inc.
> Everex StepNote Series/Everex StepNote Series
> EIP: 0060:[<f90be6c2>] EFLAGS: 00010292 CPU: 0
> EIP is at v4l2_device_release+0xa2/0xf0 [videodev]
> EAX: 00000000 EBX: f5636004 ECX: 00000000 EDX: 00000000
> ESI: f5636000 EDI: 00000000 EBP: f563600c ESP: f5627e38
>  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
> Process khubd (pid: 171, ti=f5626000 task=f554dc00 task.ti=f5626000)
> Stack:
>  ef000480 c1433780 f5474b00 c12343f8 f54e7e1c 00000000 c114737a f563600c
>  f5636028 c114605d f5636028 c1146020 f91512d4 00000000 c114737a f54e7e1c
>  f54e7e00 f81623f4 f56d4000 f54e7e1c f91512d4 f56d4064 00000001 c12373b7
> Call Trace:
>  [<c12343f8>] ? device_release+0x18/0x80
>  [<c114737a>] ? kref_put+0x2a/0x60
>  [<c114605d>] ? kobject_release+0x3d/0xa0
>  [<c1146020>] ? kobject_del+0x30/0x30
>  [<c114737a>] ? kref_put+0x2a/0x60
>  [<f81623f4>] ? usb_unbind_interface+0x34/0x130 [usbcore]
>  [<c12373b7>] ? __device_release_driver+0x57/0xb0
>  [<c123742d>] ? device_release_driver+0x1d/0x30
>  [<c1236fc2>] ? bus_remove_device+0x72/0x90
>  [<c12350bf>] ? device_del+0xdf/0x150
>  [<f8160591>] ? usb_disable_device+0x81/0x180 [usbcore]
>  [<f8159b3b>] ? usb_disconnect+0x8b/0x110 [usbcore]
>  [<f815b76c>] ? hub_thread+0x97c/0x1180 [usbcore]
>  [<c102d80b>] ? pick_next_task_fair+0x8b/0xe0
>  [<c1052600>] ? abort_exclusive_wait+0x90/0x90
>  [<f815adf0>] ? usb_remote_wakeup+0x40/0x40 [usbcore]
>  [<c1052029>] ? kthread+0x69/0x70
>  [<c1051fc0>] ? kthread_worker_fn+0x150/0x150
>  [<c130d8be>] ? kernel_thread_helper+0x6/0xd
> Code: 83 94 01 00 00 c7 83 60 01 00 00 00 00 00 00 0f b7 93 9c 01 00
> 00 c1 e0 05 f0 0f b3 90 c0 e7 0c f9 b8 20 e1 0c f9 e8 4e cf 24 c8
> <8b> 57 6c 89 f0 85 d2 74 25 ff 93 c8 01 00 00 85 ff 74 21 89 f8
> EIP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev] SS:ESP
> 0068:f5627e38
> CR2: 000000000000006c
> ---[ end trace 39522f0f1757c8f8 ]---


The trace hints at a v4l2 being NULL in a newly introduced
v4l2_dev->release check. Attached patch below.

Regards,
Frederik

[media] v4l: Avoid NULL pointer dereference

8280b662df96f4172c4972b14a4aec0daf272b8f introduced a potential NULL
deref in the case v4l2_dev is NULL.

Reported-by: Tomas M. <tmezzadra@gmail.com>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu>

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index d721565..5c0fa64 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -181,7 +181,7 @@ static void v4l2_device_release(struct device *cd)
 	 * TODO: In the long run all drivers that use v4l2_device should use the
 	 * v4l2_device release callback. This check will then be unnecessary.
 	 */
-	if (v4l2_dev->release == NULL)
+	if (v4l2_dev != NULL && v4l2_dev->release == NULL)
 		v4l2_dev = NULL;
 
 	/* Release video_device and perform other

Re: kernel OOPS when releasing usb webcam (random)

[Antonio Ospite]

[-- Attachment #1: Type: text/plain, Size: 1014 bytes --]

On Mon, 17 Oct 2011 17:05:19 -0700 (PDT)
David Rientjes <rientjes@google.com> wrote:

> On Mon, 17 Oct 2011, Tomas M. wrote:
> 
> > im getting the following null pointer dereference from time to time when
> > releasing a usb camera.
> > 
> > maybe this trace is of assistance...please reply to my mail since im not
> > subscribed.
> > 
> 
> I suspect this is happening in v4l2_device_unregister_subdev().  Adding 
> Guennadi, Mauro, and linux-media.
> 
> > BUG: unable to handle kernel NULL pointer dereference at 0000006c
> > IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]

Hi,

I sent a fix for a similar trace last week:
http://patchwork.linuxtv.org/patch/8124/

Tomas, can you test it fixes the problem for you too?

Thanks,
   Antonio

-- 
Antonio Ospite
http://ao2.it

PGP public key ID: 0x4553B001

A: Because it messes up the order in which people normally read text.
   See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?

[-- Attachment #2: Type: application/pgp-signature, Size: 198 bytes --]

Re: [patch] Avoid NULL deref in v4l2_device_release (was Re: kernel OOPS when releasing usb webcam (random))

[Tomas M.]

Hi Everyone,

Yes, this appears to have fixed the issue.

thanks!

On 10/17/2011 09:19 PM, Frederik Deweerdt wrote:
> [Adding relevant people to CCs]
>
> Hi Tomas,
>
> On Mon, Oct 17, 2011 at 07:48:34PM -0300, Tomas M. wrote:
>> im getting the following null pointer dereference from time to time
>> when releasing a usb camera.
>>
> [...]
>> BUG: unable to handle kernel NULL pointer dereference at 0000006c
>> IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]
>> *pde = 00000000
>> Oops: 0000 [#1] PREEMPT SMP
>> Modules linked in: fuse arc4 rt73usb rt2x00usb rt2x00lib mac80211
>> cfg80211 rfkill gspca_zc3xx gspca_main videodev joydev
>> snd_hda_codec_si3054 sg 8139too snd_hda_codec_realtek firewire_ohci
>> firewire_core mmc_core snd_hda_intel snd_hda_codec snd_hwdep snd_pcm
>> snd_timer snd soundcore mii crc_itu_t snd_page_alloc iTCO_wdt
>> iTCO_vendor_support i2c_i801 evdev psmouse thermal battery serio_raw
>> ac cpufreq_ondemand acpi_cpufreq freq_table processor mperf usbhid
>> hid ext3 jbd mbcache sd_mod sr_mod cdrom pata_acpi uhci_hcd ata_piix
>> ehci_hcd libata scsi_mod usbcore [last unloaded: sdhci]
>>
>> Pid: 171, comm: khubd Not tainted 3.1.0-rc9 #66 Everex Systems, Inc.
>> Everex StepNote Series/Everex StepNote Series
>> EIP: 0060:[<f90be6c2>] EFLAGS: 00010292 CPU: 0
>> EIP is at v4l2_device_release+0xa2/0xf0 [videodev]
>> EAX: 00000000 EBX: f5636004 ECX: 00000000 EDX: 00000000
>> ESI: f5636000 EDI: 00000000 EBP: f563600c ESP: f5627e38
>>   DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
>> Process khubd (pid: 171, ti=f5626000 task=f554dc00 task.ti=f5626000)
>> Stack:
>>   ef000480 c1433780 f5474b00 c12343f8 f54e7e1c 00000000 c114737a f563600c
>>   f5636028 c114605d f5636028 c1146020 f91512d4 00000000 c114737a f54e7e1c
>>   f54e7e00 f81623f4 f56d4000 f54e7e1c f91512d4 f56d4064 00000001 c12373b7
>> Call Trace:
>>   [<c12343f8>] ? device_release+0x18/0x80
>>   [<c114737a>] ? kref_put+0x2a/0x60
>>   [<c114605d>] ? kobject_release+0x3d/0xa0
>>   [<c1146020>] ? kobject_del+0x30/0x30
>>   [<c114737a>] ? kref_put+0x2a/0x60
>>   [<f81623f4>] ? usb_unbind_interface+0x34/0x130 [usbcore]
>>   [<c12373b7>] ? __device_release_driver+0x57/0xb0
>>   [<c123742d>] ? device_release_driver+0x1d/0x30
>>   [<c1236fc2>] ? bus_remove_device+0x72/0x90
>>   [<c12350bf>] ? device_del+0xdf/0x150
>>   [<f8160591>] ? usb_disable_device+0x81/0x180 [usbcore]
>>   [<f8159b3b>] ? usb_disconnect+0x8b/0x110 [usbcore]
>>   [<f815b76c>] ? hub_thread+0x97c/0x1180 [usbcore]
>>   [<c102d80b>] ? pick_next_task_fair+0x8b/0xe0
>>   [<c1052600>] ? abort_exclusive_wait+0x90/0x90
>>   [<f815adf0>] ? usb_remote_wakeup+0x40/0x40 [usbcore]
>>   [<c1052029>] ? kthread+0x69/0x70
>>   [<c1051fc0>] ? kthread_worker_fn+0x150/0x150
>>   [<c130d8be>] ? kernel_thread_helper+0x6/0xd
>> Code: 83 94 01 00 00 c7 83 60 01 00 00 00 00 00 00 0f b7 93 9c 01 00
>> 00 c1 e0 05 f0 0f b3 90 c0 e7 0c f9 b8 20 e1 0c f9 e8 4e cf 24 c8
>> <8b>  57 6c 89 f0 85 d2 74 25 ff 93 c8 01 00 00 85 ff 74 21 89 f8
>> EIP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev] SS:ESP
>> 0068:f5627e38
>> CR2: 000000000000006c
>> ---[ end trace 39522f0f1757c8f8 ]---
>
> The trace hints at a v4l2 being NULL in a newly introduced
> v4l2_dev->release check. Attached patch below.
>
> Regards,
> Frederik
>
> [media] v4l: Avoid NULL pointer dereference
>
> 8280b662df96f4172c4972b14a4aec0daf272b8f introduced a potential NULL
> deref in the case v4l2_dev is NULL.
>
> Reported-by: Tomas M.<tmezzadra@gmail.com>
> Signed-off-by: Frederik Deweerdt<frederik.deweerdt@xprog.eu>
>
> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
> index d721565..5c0fa64 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -181,7 +181,7 @@ static void v4l2_device_release(struct device *cd)
>   	 * TODO: In the long run all drivers that use v4l2_device should use the
>   	 * v4l2_device release callback. This check will then be unnecessary.
>   	 */
> -	if (v4l2_dev->release == NULL)
> +	if (v4l2_dev != NULL&&  v4l2_dev->release == NULL)
>   		v4l2_dev = NULL;
>
>   	/* Release video_device and perform other
>

Re: kernel OOPS when releasing usb webcam (random)

[David Rientjes]

On Tue, 18 Oct 2011, Antonio Ospite wrote:

> > > im getting the following null pointer dereference from time to time when
> > > releasing a usb camera.
> > > 
> > > maybe this trace is of assistance...please reply to my mail since im not
> > > subscribed.
> > > 
> > 
> > I suspect this is happening in v4l2_device_unregister_subdev().  Adding 
> > Guennadi, Mauro, and linux-media.
> > 
> > > BUG: unable to handle kernel NULL pointer dereference at 0000006c
> > > IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]
> 
> Hi,
> 
> I sent a fix for a similar trace last week:
> http://patchwork.linuxtv.org/patch/8124/
> 
> Tomas, can you test it fixes the problem for you too?
> 

Tomas reported that the same change from Frederik Deweerdt fixed the 
issue, so you can add his tested-by from 
https://lkml.org/lkml/2011/10/18/298.

Guennadi or Mauro, how is this going to Linus?  It sounds like 3.1 
material since we've received at least a couple of reports of this in the 
past week.

Re: kernel OOPS when releasing usb webcam (random)

[David Rientjes]

On Tue, 18 Oct 2011, David Rientjes wrote:

> Guennadi or Mauro, how is this going to Linus?  It sounds like 3.1 
> material since we've received at least a couple of reports of this in the 
> past week.
> 

This fix is now in Linus' tree at e58fced201ad ("[media] videodev: fix a 
NULL pointer dereference in v4l2_device_release()") for 3.1.

Re: kernel OOPS when releasing usb webcam (random)

[Mauro Carvalho Chehab]

Em 19-10-2011 18:21, David Rientjes escreveu:
> On Tue, 18 Oct 2011, David Rientjes wrote:
> 
>> Guennadi or Mauro, how is this going to Linus?  It sounds like 3.1 
>> material since we've received at least a couple of reports of this in the 
>> past week.
>>
> 
> This fix is now in Linus' tree at e58fced201ad ("[media] videodev: fix a 
> NULL pointer dereference in v4l2_device_release()") for 3.1.

Yes, I sent it upstream earlier today. Btw, Greg also picked it for stable.
It should be there for the next 3.0.x kernel as well.

Regards,
Mauro