Re: PROBLEM: System call 'sendmsg' of process ospfd (quagga)causes kernel oops

From: Herbert Xu
Date: Wed Oct 19 2011 - 04:08:18 EST


On Wed, Oct 19, 2011 at 03:30:52AM -0400, David Miller wrote:
> From: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Date: Wed, 19 Oct 2011 09:18:33 +0200
>
> > Seems fine (Maybe do the +15 in caller site ?), but we also have other
> > problematic cases, using alloc_skb() only...
>
> Ok, which ones operate over these problematic GRE tunnels?

Potentially all of them since we now support Ethernet-over-GRE.

I think Eric's initial patch is probably the safest bet for rc10.
We can then work on the proper fix for the next release.

As to the latter, I've just done a grep over net and it seems that
all users of LL_ALLOCATED_SPACE fall into two cases, alloc_skb users
or sock_alloc_send_skb (including pskb) users.

For alloc_skb we could add a new helper. While for the other
case we could either create a new helper or just add an extra
dev argument that may be NULL for those that don't care about
LL_ALLOCATED_SPACE.

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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