From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Willy Tarreau <w@1wt.eu>
Cc: David Miller <davem@davemloft.net>,
Eric Dumazet <eric.dumazet@gmail.com>,
netdev@vger.kernel.org, stable@vger.kernel.org
Subject: Re: for 3.0 : please add "c16a98e ipv6: tcp: fix panic in SYN processing"
Date: Fri, 18 Oct 2013 07:34:33 -0700 [thread overview]
Message-ID: <20131018143433.GA27502@kroah.com> (raw)
In-Reply-To: <20131018140442.GA16883@1wt.eu>
On Fri, Oct 18, 2013 at 04:04:42PM +0200, Willy Tarreau wrote:
> Greg, David,
>
> one of our customers faced a panic in latest 2.6.32 when both somaxconn
> and the listen backlog are large on an IPv6 socket. It was also reported
> by one haproxy user on the latest RHEL6 kernel a few months ago. We found
> that the same bug affects 3.0 up to and including 3.0.100.
>
> Eric had already spotted that bug and fixed it in 3.2 with the following
> patch :
>
> commit c16a98ed91597b40b22b540c6517103497ef8e74
> Author: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Wed Nov 23 15:49:31 2011 -0500
>
> ipv6: tcp: fix panic in SYN processing
>
> commit 72a3effaf633bc ([NET]: Size listen hash tables using backlog
> hint) added a bug allowing inet6_synq_hash() to return an out of bound
> array index, because of u16 overflow.
>
> Bug can happen if system admins set net.core.somaxconn &
> net.ipv4.tcp_max_syn_backlog sysctls to values greater than 65536
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
>
> In practice, the bug extends to lower values as well (32768 and above),
> because reqsk_queue_alloc() can round the number of entries to double of
> the backlog by doing roundup_pow_of_two(backlog+1), resulting in
> inet6_csk_search_req() calling inet6_synq_hash() with too large an integer.
>
> Could we please apply it to 3.0 before it finishes its life ?
Unless David objects, I can queue this up just in time for the last
3.0.stable.
David?
next prev parent reply other threads:[~2013-10-18 14:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-18 14:04 for 3.0 : please add "c16a98e ipv6: tcp: fix panic in SYN processing" Willy Tarreau
2013-10-18 14:34 ` Greg Kroah-Hartman [this message]
2013-10-18 17:31 ` David Miller
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