Kernel Oops - BUG: unable to handle kernel NULL pointer dereference at 00000004; EIP is at slave_alloc+0x2e/0x60 [usb_storage]

Note that it crashes on amd64 too (so it's reproducible). Attached corresponding dmesg.

Linux voyager 2.6.26-5-generic #1 SMP Fri Aug 15 13:54:22 UTC 2008 x86_64 GNU/Linux
Ubuntu 2.6.26-5.17-generic

You don't seem to be the only person with this problem: http://article.gmane.org/gmane.linux.usb.general/8525

The Ubuntu Kernel Team is planning to move to the 2.6.27 kernel for the upcoming Intrepid Ibex 8.10 release. As a result, the kernel team would appreciate it if you could please test this newer 2.6.27 Ubuntu kernel. There are one of two ways you should be able to test:

1) If you are comfortable installing packages on your own, the linux-image-2.6.27-* package is currently available for you to install and test.

--or--

2) The upcoming Alpha5 for Intrepid Ibex 8.10 will contain this newer 2.6.27 Ubuntu kernel. Alpha5 is set to be released Thursday Sept 4. Please watch http://www.ubuntu.com/testing for Alpha5 to be announced. You should then be able to test via a LiveCD.

Please let us know immediately if this newer 2.6.27 kernel resolves the bug reported here or if the issue remains. More importantly, please open a new bug report for each new bug/regression introduced by the 2.6.27 kernel and tag the bug report with 'linux-2.6.27'. Also, please specifically note if the issue does or does not appear in the 2.6.26 kernel. Thanks again, we really appreicate your help and feedback.

The Intrepid Ibex 8.10 Beta release was most recently announced - http://www.ubuntu.com/testing/intrepid/beta . It contains the 2.6.27 Ubuntu kernel. It would be great if you could test and verify if this is still an issue. The status is being set to Incomplete until we receive further feedback. Thanks.

well, with 2.6.27, the oops is gone but I'm no longer able to mount this USB key at all.

[1036217.812031] usb 5-3: new high speed USB device using ehci_hcd and address 12
[1036217.945586] usb 5-3: configuration #1 chosen from 1 choice
[1036217.947574] scsi4 : SCSI emulation for USB Mass Storage devices
[1036217.948826] usb-storage: device found at 12
[1036217.948833] usb-storage: waiting for device to settle before scanning
[1036222.949145] usb-storage: device scan complete
[1036228.560034] usb 5-3: reset high speed USB device using ehci_hcd and address 12
[1036243.672044] usb 5-3: device descriptor read/64, error -110
[1036258.892033] usb 5-3: device descriptor read/64, error -110
[1036259.108030] usb 5-3: reset high speed USB device using ehci_hcd and address 12
[1036274.220030] usb 5-3: device descriptor read/64, error -110
[1036289.436030] usb 5-3: device descriptor read/64, error -110
[1036289.652032] usb 5-3: reset high speed USB device using ehci_hcd and address 12
[1036300.060020] usb 5-3: device not accepting address 12, error -110
[1036300.172032] usb 5-3: reset high speed USB device using ehci_hcd and address 12
[1036310.580019] usb 5-3: device not accepting address 12, error -110
[1036310.581063] usb 5-3: USB disconnect, address 12
[1036310.583357] scsi 4:0:0:0: Device offlined - not ready after error recovery
[1036310.696037] usb 5-3: new high speed USB device using ehci_hcd and address 13
...

this is covered by tons of other bugs.

I've used the very same key on several (Ubuntu) PCs before, without any issue. Now, none of them is able to mount it, yet it works just fine on non-linux PCs. This is a clear regression for me.

Thanks for your reply.
I'm marking it as confirmed again.

Hi Fabien,

What if you "sudo rmmod ehci_hcd" before you insert the usb stick - see Bug 88746 .

Per a decision made by the Ubuntu Kernel Team, bugs will longer be assigned to the ubuntu-kernel-team in Launchpad as part of the bug triage process. The ubuntu-kernel-team is being unassigned from this bug report. Refer to https://wiki.ubuntu.com/KernelTeamBugPolicies for more information. Thanks.

Fabien Tassin, thank you for reporting this and helping make Ubuntu better. Intrepid reached EOL on April 30, 2010.
Please see this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We were wondering if this is still an issue on a supported release? If so, can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command in a supported release from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux <replace-with-bug-number>

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]