Kernel oops when inserting a Usb camera with usb audio (pulseaudio related)

Bug #528753 reported by Raffaello D. Di Napoli
28
This bug affects 3 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Expired
Undecided
Unassigned

Bug Description

Please note I don’t have direct access to the computer (HP Pavilion dv5000), as it’s some 10 000 km away from me :)

That said, the problem is with Ubuntu Desktop Karmic, with kernels ranging from 2.6.31.15 to 2.6.31.19; they all exhibit the same behavior due to a slightly worn out USB socket, which makes the webcam USB plug connect and reconnect all of sudden and very quickly.

Please note that the webcam is a Logitech Webcam C200, which includes a sound device (mic in). This USB sound device seems to be the actual cause of the oops, not the video device (uvcvideo). In fact, when using an external microphone along with the sole video from the webcam, the above mentioned disconnection only causes a loss of video, but reactivating it (in the worst case, after replugging the webcam) always gets the video back working. When the audio device is also used, instead... keep on reading.

Actual results:
If the sudden disconnection happens while a program (e.g. Skype) is reading from the webcam, the kernel goes oops (see attached dmesg), and the following symptoms ensue:
· the webcam won’t work anymore
· anything sound-related won’t work either
· trying to start System > Preferences > Sound will hang with a message “Waiting for sound system to respond”
· closing Skype won’t work
· System Monitor won’t start, and trying to run “ps aux” will cause the terminal to hang
· trying to reboot will hang indefinitely at some point after shutting down X (so on some init.d script), requiring forced power off

Expected results:
Programs using the webcam might crash, freeze, stop reading from the webcam, but the kernel should stay stable and the remedy should be to just reinsert the USB plug and reactivate the video in the program.

The dmesg was taken with kernel 2.6.31.17, but the remaining files are from 2.6.31.15 (which seems to be more stable with hibernation). I hope that’s not a big deal. Also, the dmesg is partial, since it had to be sent via the Skype chat window, that’s not exactly designed for this purpose :) I hope I got all the relevant parts, though.

Revision history for this message
Raffaello D. Di Napoli (raffaellod) wrote :
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Raffaello D. Di Napoli (raffaellod) wrote :
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Raffaello D. Di Napoli (raffaellod) wrote :
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Raffaello D. Di Napoli (raffaellod) wrote :
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Anzenketh (anzenketh) wrote :

Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at https://wiki.ubuntu.com/Bugs/FindRightPackage. I have classified this bug as a bug in linux.

When reporting bugs in the future please use apport, either via the appropriate application's "Help -> Report a Problem" menu or using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

affects: ubuntu → linux (Ubuntu)
Changed in linux (Ubuntu):
status: New → Incomplete
status: Incomplete → New
Revision history for this message
Anzenketh (anzenketh) wrote :

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue that you reported is one that should be reproducible with the live environment of the Desktop CD of the development release - Lucid. It would help us greatly if you could test with it so we can work on getting it fixed in the next release of Ubuntu. You can find out more about the development release at http://www.ubuntu.com/testing/. Thanks again and we appreciate your help.

summary: - snd_usb_audio - NULL pointer dereference in usb_ifnum_to_if+0x18/0x50
+ Kernel oops when inserting a Usb camera with usb audio (pulseaudio
+ related)
Changed in linux (Ubuntu):
status: New → Incomplete
tags: added: kernel-series-unknown
tags: added: karmic
removed: kernel-series-unknown
Revision history for this message
Jeremy Foshee (jeremyfoshee) wrote :

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

tags: added: kj-expired
Changed in linux (Ubuntu):
status: Incomplete → Expired
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