linux-kernel - Re: [BUG] 2.6.21 hang in cancel_rearming_delayed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Fri, 25 May 2007 08:21:23 -0500
From:	Jason Wessel <jason.wessel@...driver.com>
To:	Jarek Poplawski <jarkao2@...pl>
CC:	linux-kernel@...r.kernel.org
Subject: Re: [BUG] 2.6.21 hang in cancel_rearming_delayed_workqueue()

Jarek Poplawski wrote:
> On 25-05-2007 05:21, Jason Wessel wrote:
>   
>> There is a problem with the calling cancel_rearming_delayed_work if the 
>> timer was not yet active.
>>
>>
>> It is possible that the problem exists else where, but I thought I would 
>> ask if this is expected?
>>
>>     
>
>
> " * cancel_rearming_delayed_workqueue - reliably kill off a delayed
>  work whose handler rearms the delayed work."
>
> So, it cannot be used in netpoll_cleanup() if there is no rearming
> during this cancel at all. This is a tricky behaviour of course,
> and is changed in 2.6.22-rc.
>
>   

I had read that as well.  It seems this the API for the cancel is 
restricted such that you cannot call it if there is nothing to cancel.

This means the netpoll code is incorrect and the simple fix is 
attached.  With the change the netpoll_cleanup works correctly in 2.6.21.

Thanks,
Jason.

View attachment "netpoll_workqueue_fix.patch" of type "text/plain" (842 bytes)