From 71b1391a41289735676be02e35239e5aa9fe6ba6 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 25 Nov 2011 06:47:16 +0000 Subject: l2tp: ensure sk->dst is still valid When using l2tp over ipsec, the tunnel will hang when rekeying occurs. Reason is that the transformer bundle attached to the dst entry is now in STATE_DEAD and thus xfrm_output_one() drops all packets (XfrmOutStateExpired increases). Fix this by calling __sk_dst_check (which drops the stale dst if xfrm dst->check callback finds that the bundle is no longer valid). Cc: James Chapman Signed-off-by: Florian Westphal Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/l2tp') diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index cf0f308abf5e..89ff8c67943e 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1072,7 +1072,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len /* Get routing info from the tunnel socket */ skb_dst_drop(skb); - skb_dst_set(skb, dst_clone(__sk_dst_get(sk))); + skb_dst_set(skb, dst_clone(__sk_dst_check(sk, 0))); inet = inet_sk(sk); fl = &inet->cork.fl; -- cgit v1.2.3 From 68315801dbf3ab2001679fd2074c9dc5dcf87dfa Mon Sep 17 00:00:00 2001 From: James Chapman Date: Wed, 25 Jan 2012 02:39:05 +0000 Subject: l2tp: l2tp_ip - fix possible oops on packet receive When a packet is received on an L2TP IP socket (L2TPv3 IP link encapsulation), the l2tpip socket's backlog_rcv function calls xfrm4_policy_check(). This is not necessary, since it was called before the skb was added to the backlog. With CONFIG_NET_NS enabled, xfrm4_policy_check() will oops if skb->dev is null, so this trivial patch removes the call. This bug has always been present, but only when CONFIG_NET_NS is enabled does it cause problems. Most users are probably using UDP encapsulation for L2TP, hence the problem has only recently surfaced. EIP: 0060:[] EFLAGS: 00210246 CPU: 0 EIP is at l2tp_ip_recvmsg+0xd4/0x2a7 EAX: 00000001 EBX: d77b5180 ECX: 00000000 EDX: 00200246 ESI: 00000000 EDI: d63cbd30 EBP: d63cbd18 ESP: d63cbcf4 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Call Trace: [] sock_common_recvmsg+0x31/0x46 [] __sock_recvmsg_nosec+0x45/0x4d [] __sock_recvmsg+0x31/0x3b [] sock_recvmsg+0x96/0xab [] ? might_fault+0x47/0x81 [] ? might_fault+0x47/0x81 [] ? _copy_from_user+0x31/0x115 [] ? copy_from_user+0x8/0xa [] ? verify_iovec+0x3e/0x78 [] __sys_recvmsg+0x10a/0x1aa [] ? sock_recvmsg+0x0/0xab [] ? __lock_acquire+0xbdf/0xbee [] ? do_page_fault+0x193/0x375 [] ? fcheck_files+0x9b/0xca [] ? fget_light+0x2a/0x9c [] sys_recvmsg+0x2b/0x43 [] sys_socketcall+0x16d/0x1a5 [] ? trace_hardirqs_on_thunk+0xc/0x10 [] sysenter_do_call+0x12/0x38 Code: c6 05 8c ea a8 c1 01 e8 0c d4 d9 ff 85 f6 74 07 3e ff 86 80 00 00 00 b9 17 b6 2b c1 ba 01 00 00 00 b8 78 ed 48 c1 e8 23 f6 d9 ff 76 0c 68 28 e3 30 c1 68 2d 44 41 c1 e8 89 57 01 00 83 c4 0c Signed-off-by: James Chapman Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/l2tp/l2tp_ip.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'net/l2tp') diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index d21e7ebd91ca..55670ec3cd0f 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -393,11 +393,6 @@ static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) { int rc; - if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) - goto drop; - - nf_reset(skb); - /* Charge it to the socket, dropping if the queue is full. */ rc = sock_queue_rcv_skb(sk, skb); if (rc < 0) -- cgit v1.2.3