From: Eric Dumazet Date: Thu, 9 Aug 2012 13:56:06 +0000 (+0000) Subject: ipv4: tcp: unicast_sock should not land outside of TCP stack X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3a7c384ffd57;p=linux-beck.git ipv4: tcp: unicast_sock should not land outside of TCP stack commit be9f4a44e7d41cee (ipv4: tcp: remove per net tcp_sock) added a selinux regression, reported and bisected by John Stultz selinux_ip_postroute_compat() expect to find a valid sk->sk_security pointer, but this field is NULL for unicast_sock It turns out that unicast_sock are really temporary stuff to be able to reuse part of IP stack (ip_append_data()/ip_push_pending_frames()) Fact is that frames sent by ip_send_unicast_reply() should be orphaned to not fool LSM. Note IPv6 never had this problem, as tcp_v6_send_response() doesnt use a fake socket at all. I'll probably implement tcp_v4_send_response() to remove these unicast_sock in linux-3.7 Reported-by: John Stultz Bisected-by: John Stultz Signed-off-by: Eric Dumazet Cc: Paul Moore Cc: Eric Paris Cc: "Serge E. Hallyn" Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 76dde25fb9a0..ec410e08b4b9 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1536,6 +1536,7 @@ void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr, arg->csumoffset) = csum_fold(csum_add(nskb->csum, arg->csum)); nskb->ip_summed = CHECKSUM_NONE; + skb_orphan(nskb); skb_set_queue_mapping(nskb, skb_get_queue_mapping(skb)); ip_push_pending_frames(sk, &fl4); }