Re: BUG: unable to handle kernel NULL pointer dereference at 000000000000002c

[Eric Dumazet <eric.dumazet@gmail.com>]

Le jeudi 01 décembre 2011 à 13:23 -0500, Christoph Hellwig a écrit :
> On Thu, Dec 01, 2011 at 07:11:51PM +0100, Stefan Priebe wrote:
> > Hi,
> > 
> > i'm not quite sure if this is an XFS thing or a tcp thing. As the
> > stacktrace confuses me a little but as it contains
> > xfs_bmap_search_extents and xfs_iunlock. Kernel is 3.0.11 running as
> > 2.6.40.11.
> > 
> > [171464.091567] BUG: unable to handle kernel NULL pointer
> > dereference at 000000000000002c
> > [171464.092073] IP: [<ffffffff815494f6>] ipv4_dst_check+0xb6/0x190
> > [171464.092073] PGD 15344e067 PUD 14c821067 PMD 0
> > [171464.092073] Oops: 0002 [#1] SMP
> > 
> > Full Stacktrace:
> > http://pastebin.com/raw.php?i=QNg6jD2t
> 
> The ? entries mean even the backtrace code things they are unreliable,
> and mos of the cases I've seen they are wrong.  In this case it looks
> like the process was doing XFS work before, but the current system call
> indeed is purely in the networking code.
> 
> I've changed the cc list to the netdev list which is more appropinquate.

Probably fixed by commit 81d54ec8479a2c695760da
(net: fix NULL dereferences in check_peer_redir())

But this patch needs some followup patches (some of them in David net
tree, not yet in Linus tree)