On Fri, Dec 05, 2014 at 01:15:51AM +0200, Julian Anastasov wrote: > > Hello, > > On Thu, 4 Dec 2014, Steffen Klassert wrote: > > > > [16623.096721] Call Trace: > > > [16623.096744] <IRQ> > > > [16623.096749] [<ffffffff81547a7c>] ? xfrm_sk_policy_lookup+0x44/0x9b > > > [16623.096802] [<ffffffff81547ef7>] ? xfrm_lookup+0x91/0x446 > > > [16623.096832] [<ffffffff81541316>] ? ip_route_me_harder+0x150/0x1b0 > > > [16623.096865] [<ffffffffa01b6457>] ? ip_vs_route_me_harder+0x86/0x91 > > > [ip_vs] > > > [16623.096899] [<ffffffffa01b797a>] ? ip_vs_out+0x2d3/0x5bc [ip_vs] > > > [16623.096930] [<ffffffff81501420>] ? ip_rcv_finish+0x2b8/0x2b8 > > > > I really wonder why the xfrm_sk_policy_lookup codepath is taken here. > > It looks like this is the processing of an inbound ipv4 packet that > > is going to be rerouted to the output path by ipvs, so this packet > > should not have socket context at all. > > In above trace looks like IPVS-NAT is used between > local client and some real server. IPVS handles this skb > at LOCAL_IN and calls ip_vs_route_me_harder(). If we have > skb->sk at LOCAL_IN, my first thought is about early demux.
Yes, that's possible. Can be checked by disabling early demux. echo 0 > /proc/sys/net/ipv4/ip_early_demux If I look what it tries to dereference when the crash happens, this does not look like a pointer. But sk->sk_policy[dir] should be either a pointer to kernel memory or NULL. So I think that the skb->sk pointer is already bogus. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
