Merge branch 'master' of git://1984.lsi.us.es/nf

Pablo Neira Ayuso say:

====================
The following patchset contains four updates for your net tree, they are:

* Fix crash on timewait sockets, since the TCP early demux was added,
  in nfnetlink_log, from Eric Dumazet.

* Fix broken syslog log-level for xt_LOG and ebt_log since printk format was
  converted from <.> to a 2 bytes pattern using ASCII SOH, from Joe Perches.

* Two security fixes for the TCP connection tracking targeting off-path attacks,
  from Jozsef Kadlecsik. The problem was discovered by Jan Wrobel and it is
  documented in: http://mixedbit.org/reflection_scan/reflection_scan.pdf.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 38 insertions, 44 deletions

diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c
index f88ee537fb2..92de5e5f9db 100644
--- a/net/bridge/netfilter/ebt_log.c
+++ b/net/bridge/netfilter/ebt_log.c
@@ -80,7 +80,7 @@ ebt_log_packet(u_int8_t pf, unsigned int hooknum,
 	unsigned int bitmask;
 
 	spin_lock_bh(&ebt_log_lock);
-	printk("<%c>%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x",
+	printk(KERN_SOH "%c%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x",
 	       '0' + loginfo->u.log.level, prefix,
 	       in ? in->name : "", out ? out->name : "",
 	       eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index a5ac11ebef3..e046b3756aa 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -158,21 +158,18 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
  *	sCL -> sSS
  */
 /* 	     sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2	*/
-/*synack*/ { sIV, sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, sSR },
+/*synack*/ { sIV, sIV, sSR, sIV, sIV, sIV, sIV, sIV, sIV, sSR },
 /*
  *	sNO -> sIV	Too late and no reason to do anything
  *	sSS -> sIV	Client can't send SYN and then SYN/ACK
  *	sS2 -> sSR	SYN/ACK sent to SYN2 in simultaneous open
- *	sSR -> sIG
- *	sES -> sIG	Error: SYNs in window outside the SYN_SENT state
- *			are errors. Receiver will reply with RST
- *			and close the connection.
- *			Or we are not in sync and hold a dead connection.
- *	sFW -> sIG
- *	sCW -> sIG
- *	sLA -> sIG
- *	sTW -> sIG
- *	sCL -> sIG
+ *	sSR -> sSR	Late retransmitted SYN/ACK in simultaneous open
+ *	sES -> sIV	Invalid SYN/ACK packets sent by the client
+ *	sFW -> sIV
+ *	sCW -> sIV
+ *	sLA -> sIV
+ *	sTW -> sIV
+ *	sCL -> sIV
  */
 /* 	     sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2	*/
 /*fin*/    { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
@@ -633,15 +630,9 @@ static bool tcp_in_window(const struct nf_conn *ct,
 		ack = sack = receiver->td_end;
 	}
 
-	if (seq == end
-	    && (!tcph->rst
-		|| (seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)))
+	if (tcph->rst && seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)
 		/*
-		 * Packets contains no data: we assume it is valid
-		 * and check the ack value only.
-		 * However RST segments are always validated by their
-		 * SEQ number, except when seq == 0 (reset sent answering
-		 * SYN.
+		 * RST sent answering SYN.
 		 */
 		seq = end = sender->td_end;
 
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 14e2f390314..5cfb5bedb2b 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -381,6 +381,7 @@ __build_packet_message(struct nfulnl_instance *inst,
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
 	sk_buff_data_t old_tail = inst->skb->tail;
+	struct sock *sk;
 
 	nlh = nlmsg_put(inst->skb, 0, 0,
 			NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
@@ -499,18 +500,19 @@ __build_packet_message(struct nfulnl_instance *inst,
 	}
 
 	/* UID */
-	if (skb->sk) {
-		read_lock_bh(&skb->sk->sk_callback_lock);
-		if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
-			struct file *file = skb->sk->sk_socket->file;
+	sk = skb->sk;
+	if (sk && sk->sk_state != TCP_TIME_WAIT) {
+		read_lock_bh(&sk->sk_callback_lock);
+		if (sk->sk_socket && sk->sk_socket->file) {
+			struct file *file = sk->sk_socket->file;
 			__be32 uid = htonl(file->f_cred->fsuid);
 			__be32 gid = htonl(file->f_cred->fsgid);
-			read_unlock_bh(&skb->sk->sk_callback_lock);
+			read_unlock_bh(&sk->sk_callback_lock);
 			if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
 			    nla_put_be32(inst->skb, NFULA_GID, gid))
 				goto nla_put_failure;
 		} else
-			read_unlock_bh(&skb->sk->sk_callback_lock);
+			read_unlock_bh(&sk->sk_callback_lock);
 	}
 
 	/* local sequence number */
diff --git a/net/netfilter/xt_LOG.c b/net/netfilter/xt_LOG.c
index ff5f75fddb1..91e9af4d1f4 100644
--- a/net/netfilter/xt_LOG.c
+++ b/net/netfilter/xt_LOG.c
@@ -145,6 +145,19 @@ static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb,
 	return 0;
 }
 
+static void dump_sk_uid_gid(struct sbuff *m, struct sock *sk)
+{
+	if (!sk || sk->sk_state == TCP_TIME_WAIT)
+		return;
+
+	read_lock_bh(&sk->sk_callback_lock);
+	if (sk->sk_socket && sk->sk_socket->file)
+		sb_add(m, "UID=%u GID=%u ",
+			sk->sk_socket->file->f_cred->fsuid,
+			sk->sk_socket->file->f_cred->fsgid);
+	read_unlock_bh(&sk->sk_callback_lock);
+}
+
 /* One level of recursion won't kill us */
 static void dump_ipv4_packet(struct sbuff *m,
 			const struct nf_loginfo *info,
@@ -361,14 +374,8 @@ static void dump_ipv4_packet(struct sbuff *m,
 	}
 
 	/* Max length: 15 "UID=4294967295 " */
-	if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) {
-		read_lock_bh(&skb->sk->sk_callback_lock);
-		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
-			sb_add(m, "UID=%u GID=%u ",
-				skb->sk->sk_socket->file->f_cred->fsuid,
-				skb->sk->sk_socket->file->f_cred->fsgid);
-		read_unlock_bh(&skb->sk->sk_callback_lock);
-	}
+	if ((logflags & XT_LOG_UID) && !iphoff)
+		dump_sk_uid_gid(m, skb->sk);
 
 	/* Max length: 16 "MARK=0xFFFFFFFF " */
 	if (!iphoff && skb->mark)
@@ -436,8 +443,8 @@ log_packet_common(struct sbuff *m,
 		  const struct nf_loginfo *loginfo,
 		  const char *prefix)
 {
-	sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
-	       prefix,
+	sb_add(m, KERN_SOH "%c%sIN=%s OUT=%s ",
+	       '0' + loginfo->u.log.level, prefix,
 	       in ? in->name : "",
 	       out ? out->name : "");
 #ifdef CONFIG_BRIDGE_NETFILTER
@@ -717,14 +724,8 @@ static void dump_ipv6_packet(struct sbuff *m,
 	}
 
 	/* Max length: 15 "UID=4294967295 " */
-	if ((logflags & XT_LOG_UID) && recurse && skb->sk) {
-		read_lock_bh(&skb->sk->sk_callback_lock);
-		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
-			sb_add(m, "UID=%u GID=%u ",
-				skb->sk->sk_socket->file->f_cred->fsuid,
-				skb->sk->sk_socket->file->f_cred->fsgid);
-		read_unlock_bh(&skb->sk->sk_callback_lock);
-	}
+	if ((logflags & XT_LOG_UID) && recurse)
+		dump_sk_uid_gid(m, skb->sk);
 
 	/* Max length: 16 "MARK=0xFFFFFFFF " */
 	if (!recurse && skb->mark)