From ec831ea72ee5d7d473899e27a86bd659482c4d0d Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Mon, 31 Jan 2011 13:16:00 -0800 Subject: [PATCH] net: Add default_mtu() methods to blackhole dst_ops When an IPSEC SA is still being set up, __xfrm_lookup() will return -EREMOTE and so ip_route_output_flow() will return a blackhole route. This can happen in a sndmsg call, and after d33e455337ea ("net: Abstract default MTU metric calculation behind an accessor.") this leads to a crash in ip_append_data() because the blackhole dst_ops have no default_mtu() method and so dst_mtu() calls a NULL pointer. Fix this by adding default_mtu() methods (that simply return 0, matching the old behavior) to the blackhole dst_ops. The IPv4 part of this patch fixes a crash that I saw when using an IPSEC VPN; the IPv6 part is untested because I don't have an IPv6 VPN, but it looks to be needed as well. Signed-off-by: Roland Dreier Signed-off-by: David S. Miller --- Reading git-format-patch failed