From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexey Dobriyan <adobriyan@gmail.com>
Subject: Re: seq_read bugs with ipmr
Date: Sat, 8 Nov 2008 04:02:37 +0300
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References: <20081108002208.GB17721@alice>
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Cc: netdev@vger.kernel.org, alan@lxorguk.ukuu.org.uk
To: Eric Sesterhenn <snakebyte@gmx.de>
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On Sat, Nov 08, 2008 at 01:22:08AM +0100, Eric Sesterhenn wrote:
> running a bunch of network related stresstests (isic, isicng, ...) 
> and trying to read all files in /proc afterwards gave me two
> oopses. I was able to reproduce them on another box with
> a different config. I was able to reproduce this on 2.6.24 too,
> so this is no regression. The icmpsic is version 0.06. 
> The minimal testcase to trigger this:
> 
> ------------8<----------------
> #!/bin/bash
> 
> icmpsic -s 127.0.0.1 -d 127.0.0.1 -p 100000
> 
> find /proc/net/ | xargs cat > /dev/null
> 
> cat /proc/net/ip_mr_cache
> cat /proc/net/ip_mr_vif
> ------------8<----------------
> 
> 
> root@computer-desktop:~/testing# cat /proc/338/net/ip_mr_cache
> 
> [ 1572.702100] BUG: unable to handle kernel NULL pointer dereference at 000001c1
> [ 1572.702588] IP: [<c05942c6>] ipmr_mfc_seq_show+0x26/0xf0

Reproduced.