kmalloc_index() warning on WLAN disconnect

[Martin Emrich]

Binary package hint: linux-source-2.6.22

Since 2.6.22-5, my kernel emits the following message:

{ 76.996000] WARNING: at /build/buildd/linux-source-2.6.22-2.6.22/include/linux/slub_def.h:77 kmalloc_index()
[ 77.000000] [<c017d403>] get_slab+0x1b3/0x230
[ 77.000000] [<c017d546>] __kmalloc+0x16/0xa0
[ 77.000000] [<f8c9da62>] ieee80211_ioctl_setoptie+0x62/0xf0 [wlan]
[ 77.000000] [<c02edfab>] wext_handle_ioctl+0x30b/0x420
[ 77.000000] [<f8c9da00>] ieee80211_ioctl_setoptie+0x0/0xf0 [wlan]
[ 77.000000] [<c0276a80>] sock_ioctl+0x0/0x210
[ 77.000000] [<c0283fa2>] dev_ioctl+0x332/0x340
[ 77.000000] [<c019447e>] destroy_inode+0x2e/0x50
[ 77.000000] [<c0276a80>] sock_ioctl+0x0/0x210
[ 77.000000] [<c018cd7b>] do_ioctl+0x2b/0x90
[ 77.000000] [<c018ce3c>] vfs_ioctl+0x5c/0x290
[ 77.000000] [<c018d0e2>] sys_ioctl+0x72/0x90
[ 77.000000] [<c01041d2>] sysenter_past_esp+0x6b/0xa9
[ 77.000000] [<c02f0000>] __mutex_lock_interruptible_slowpath+0xb0/0xd0
[ 77.000000] =======================

It normally happens after my wireless connection is disconnected (I have an atheros card). After the message, the kernel becomes very unstable (applications do no longer start, sometimes the entire system freezes). So maybe it is actually related to the madwifi drivers in linux-restricted-modules-source, so feel free to move it.

[Martin Emrich (emme)]

I investigated a little further:

- The instability seems not to come every time, maybe it is triggered by some additional event.
- After the bug appears, suspend-to-ram is no longer possible: Instead of suspending, the notebook sits there unresponsive for ca. 30 seconds (only the mouse moves), and comes back to life after that.
- When I disable network-manager, the problem does not appear. Actually, I was able to "rmmod -f ath_pci" et.al. directly after the message appears, kill all network-manger-related processes, reload ath_pci, and use my wireless LAN "just like in the old days". Standby also works when I use my WLAN this way.

[Michael B. Trausch (mtrausch)]

+1 on this bug being exhibited:

[ 68.640000] WARNING: at /build/buildd/linux-source-2.6.22-2.6.22/include/linux/slub_def.h:77 kmalloc_index()
[ 68.640000] [<c017d403>] get_slab+0x1b3/0x230
[ 68.640000] [<c017d546>] __kmalloc+0x16/0xa0
[ 68.640000] [<f8cd5a62>] ieee80211_ioctl_setoptie+0x62/0xf0 [wlan]
[ 68.640000] [<c02edfab>] wext_handle_ioctl+0x30b/0x420
[ 68.640000] [<f8cd5a00>] ieee80211_ioctl_setoptie+0x0/0xf0 [wlan]
[ 68.640000] [<c0276a80>] sock_ioctl+0x0/0x210
[ 68.640000] [<c0283fa2>] dev_ioctl+0x332/0x340
[ 68.640000] [<c013bcc0>] autoremove_wake_function+0x0/0x50
[ 68.640000] [<c0276a80>] sock_ioctl+0x0/0x210
[ 68.640000] [<c018cd7b>] do_ioctl+0x2b/0x90
[ 68.640000] [<c018ce3c>] vfs_ioctl+0x5c/0x290
[ 68.640000] [<c018d0e2>] sys_ioctl+0x72/0x90
[ 68.640000] [<c01041d2>] sysenter_past_esp+0x6b/0xa9

Appeared in my system log as well. Toshiba Satellite A55-S1064, Atheros WiFi built-in. Additional information can be provided if needed.

[Juan Pablo Salazar Bertín (snifer)]

This is just a warning, but should probably be fixed in madwifi to prevent trying to allocate 0 bytes of memory.
I think it's happening here: http://madwifi.org/browser/tags/release-0.9.3/net80211/ieee80211_wireless.c#L2945

[Juan Pablo Salazar Bertín (snifer)]

the kernel bug is not about kmalloc_index(), but about drm instead.

[Jonathan Thomas (echidnaman)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue for you. Can you try with the latest Ubuntu release? Thanks in advance.

[Martin Emrich (emme)]

I never experienced this with 8.04, 8.10 or 9.04. As Ubuntu 7.10 will be EOL in a few days, I would say this bug can be closed.

[Sergio Zanchetta (primes2h)]

The 18 month support period for Gutsy Gibbon 7.10 has reached its end of life -
http://www.ubuntu.com/news/ubuntu-7.10-eol . As a result, we are closing the
linux-restricted-modules-2.6.22 task.