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:

quoted

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)