kernel OOPS when releasing usb webcam (random)

PATCH In review Tomas M. 5 participants 8 messages Oct 17, 2011 – Oct 20, 2011 Media (V4L/DVB)

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Tomas M.

author

2011-10-17 22:48 UTC #0 lore raw

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 ]---

David Rientjes

2011-10-18 00:05 UTC #1 lore raw

Quoted 6 lines · 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.

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

Quoted 52 lines

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 ]---

Antonio Ospite

2011-10-18 08:43 UTC #2 lore raw

Quoted 5 lines · On Mon, 17 Oct 2011 17:05:19 -0700 (PDT) David Rientjes <[email protected]>…

Quoted 3 lines · Tomas M.
im getting the following null pointer dereference from time to time when releasing a usb camera.

Quoted 9 lines

Quoted 3 lines
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.
Quoted 2 lines
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

Signature · 8 lines

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?

David Rientjes

2011-10-18 20:39 UTC #3 lore raw

Quoted 13 lines · Antonio Ospite

Quoted 12 lines
Quoted 6 lines
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.
Quoted 2 lines
BUG: unable to handle kernel NULL pointer dereference at 0000006c
IP: [<f90be6c2>] v4l2_device_release+0xa2/0xf0 [videodev]

Quoted 7 lines

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.

David Rientjes

2011-10-19 20:22 UTC #4 lore raw

Quoted 4 lines · David Rientjes

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.

Mauro Carvalho Chehab

2011-10-20 03:40 UTC #5 lore raw

Em 19-10-2011 18:21, David Rientjes escreveu:

Quoted 9 lines · David Rientjes

Quoted 5 lines
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

Frederik Deweerdt

2011-10-18 00:19 UTC #6 lore raw

PATCH 1/1 Avoid NULL deref in v4l2_device_release (was Re: kernel OOPS when releasing usb webcam (random))

In reply to Tomas M.

[Adding relevant people to CCs]

Hi Tomas,

Quoted 3 lines · Tomas M.

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

[...]

Quoted 47 lines

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

Quoted 6 lines

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. <[email protected]>

Signed-off-by Frederik Deweerdt <[email protected]>

drivers/media/video/v4l2-dev.c +1 -1

index d721565..5c0fa64 100644
@@ -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

Tomas M.

author

2011-10-18 15:37 UTC #7 lore raw

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

Hi Everyone,

Yes, this appears to have fixed the issue.

thanks!

Quoted 91 lines · Frederik Deweerdt

[Adding relevant people to CCs]
Hi Tomas,
Quoted 3 lines · Tomas M.
im getting the following null pointer dereference from time to time when releasing a usb camera.
[...]
Quoted 47 lines
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
Quoted 6 lines
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.<[email protected]>
Signed-off-by Frederik Deweerdt<[email protected]>
drivers/media/video/v4l2-dev.c +1 -1
index d721565..5c0fa64 100644
@@ -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