Red Hat Bugzilla – Bug 808095
kernel crash at ieee80211_mgd_probe_ap_send
Last modified: 2013-01-10 23:10:24 EST
Created attachment 573698 [details]
Kernel crash photo taken by customer.
Created attachment 575452 [details]
This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products. This request is not yet committed for inclusion in an Update release.
This panic can be reproduced by configuring one ESS wireless network on two or more APs. Each AP on different channel (simple description for linksys routers is here: http://homecommunity.cisco.com/t5/Access-Points/WRT610N-setup-as-access-point/td-p/321732 ). And then use scripts to roam between APs: http://bombadil.infradead.org/~mcgrof/test-roam
So the fix in comment 3 is similar to code in upstream commit b9dcf712, which should be covered by the other wireless updates in rhel 6.3. Should either commit b9dcf712 or the fix from comment 3 be proposed as a 6.2.z fix as well?
Yes, the patch should be backported to 6.2.z .
Unfortunately I'm still seeing that crash, however it's harder to reproduce it with a patch. Anyway some more fixes are needed to address this bug.
Remaining crashes I'm observing while doing roaming (as described in comment 6) is technically different issue. I'll open a new bug report for it. Let's proceed with fixfrom this bug report, it make roaming issues less frequent in real world environment.
Since fix only mitigate the problem, it does not make sense of doing a QE for it. I'm closing this as duplicate of RHEL6.3 wireless update. Complete fix for wireless roaming crashes are expected to be done as patch for bug 814674.
We opened bug 814657 for applying this particular fix in RHEL-6.2.z
*** This bug has been marked as a duplicate of bug 766952 ***
Created attachment 580142 [details]
Patch make problem less reproducible, but issue is not fixed. Here is another photo with the crash. Hopefully fix for bug 814674, will make it gone for sure.
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While doing wireless roaming, under stressed conditions, an error could occur in the ieee80211_mgd_probe_ap_send() function and cause a kernel panic. With this update, the mac80211 MLME (MAC Layer Management Entity) code has been rewritten, thus fixing this bug.