Messages in this thread Patch in this message | | | Date | Sun, 13 Apr 2008 22:18:54 +0200 | From | Patrick McHardy <> | Subject | Re: 2.6.25-rc9: Reported regressions from 2.6.24 |
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Patrick McHardy wrote: >>> >>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=10323 >>> Subject : panic using bridging on linus kernel 2.6.25-rc6 >>> Submitter : Andy Gospodarek <andy@greyhouse.net> >>> Date : 2008-03-25 11:40 (20 days old) >> >> This looks like another network-namespace regression. >> icmp_send() does: >> >> net = rt->u.dst.dev->nd_net; >> >> The bridge netfilter code attaches a fake dst_entry to the >> skb which has dev == NULL when passing it to IPv4 netfilter. >> >> Pavel, do you have a better ideas for fixing this than >> instantiating a dst_entry in br_netfilter.c for every >> device (or at least for every namespace)? > > The description of the problem was not entirely correct, the > bridge-netfilter dst_entry does have a proper device pointer, > it points to a dummy net_device structure however that doesn't > have a namespace associated with it. This blows up in > __ip_route_output_key.
For now I suggest this fix. Andy, could you please test whether it fixes the problem?
[BRIDGE]: Fix crash in __ip_route_output_key with bridge netfilter
The bridge netfilter code attaches a fake dst_entry with a pointer to a fake net_device structure to skbs it passes up to IPv4 netfilter. This leads to crashes when the skb is passed to __ip_route_output_key when dereferencing the namespace pointer.
Since bridging can currently only operate in the init_net namespace, the easiest fix for now is to initialize the nd_net pointer of the fake net_device struct to &init_net.
Should fix bugzilla 10323: http://bugzilla.kernel.org/show_bug.cgi?id=10323
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 1c0efd8..af7e8be 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -110,7 +110,8 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb) * ipt_REJECT needs it. Future netfilter modules might * require us to fill additional fields. */ static struct net_device __fake_net_device = { - .hard_header_len = ETH_HLEN + .hard_header_len = ETH_HLEN, + .nd_net = &init_net, }; static struct rtable __fake_rtable = { | |