netdev - Re: [PATCH net] inet: frags: remove the WARN_ON from inet_evict

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 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:	Wed, 29 Oct 2014 15:22:05 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	nikolay@...hat.com
Cc:	netdev@...r.kernel.org, fw@...len.de, eric.dumazet@...il.com,
	chutzpah@...too.org
Subject: Re: [PATCH net] inet: frags: remove the WARN_ON from
 inet_evict_bucket

From: Nikolay Aleksandrov <nikolay@...hat.com>
Date: Tue, 28 Oct 2014 10:44:01 +0100

> The WARN_ON in inet_evict_bucket can be triggered by a valid case:
> inet_frag_kill and inet_evict_bucket can be running in parallel on the
> same queue which means that there has been at least one more ref added
> by a previous inet_frag_find call, but inet_frag_kill can delete the
> timer before inet_evict_bucket which will cause the WARN_ON() there to
> trigger since we'll have refcnt!=1. Now, this case is valid because the
> queue is being "killed" for some reason (removed from the chain list and
> its timer deleted) so it will get destroyed in the end by one of the
> inet_frag_put() calls which reaches 0 i.e. refcnt is still valid.
> 
> CC: Florian Westphal <fw@...len.de>
> CC: Eric Dumazet <eric.dumazet@...il.com>
> CC: Patrick McLean <chutzpah@...too.org>
> 
> Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
> Reported-by: Patrick McLean <chutzpah@...too.org>
> Signed-off-by: Nikolay Aleksandrov <nikolay@...hat.com>
> ---
> I'm sending this as a separate patch so the race fix doesn't get blocked
> in case I'm wrong and also it's a different issue.

Also applied, thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html