Re: 答复: [PATCH] set fake_rtable's dst to NULL to avoid kernel Oops.

Eric Dumazet
2012-03-29T08:52:05Z

On Thu, 2012-03-29 at 14:40 +0800, Peter Huang (Peng) wrote:
> We already check current kernel-3.3, it has the same problem.
>
> I am not very sure that if this modify could cause other problems or not,
> Because I don't know where fake_rtable was used.

Check net/bridge/br_netfilter.c and commits e688a6048076 (net: introduce
DST_NOPEER dst flag ) 4adf0af6818f3ea5 (bridge: send correct MTU value
in PMTU (revised))

Apparently bug is because struct net_bridge is freed while its embedded
fake_rtable is still used by some packets.

I am not sure we are allowed to NULLify skb->dst, it might break
netfilter.

Maybe real fix would be to use a non embedded dst.