Commit e46787f0 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

tcp: send_reset: test for non-NULL sk first 



tcp_md5_do_lookup requires a full socket, so once we extend
_send_reset() to also accept timewait socket we would have to change

if (!sk && hash_location)

to something like

if ((!sk || !sk_fullsock(sk)) && hash_location) {
  ...
} else {
  (sk && sk_fullsock(sk)) tcp_md5_do_lookup()
}

Switch the two branches: check if we have a socket first, then
fall back to a listener lookup if we saw a md5 option (hash_location).

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b1f0a0e9

net/ipv4/tcp_ipv4.c

+5 −6
Original line number Diff line number Diff line
@@ -587,7 +587,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
	} rep;

	struct ip_reply_arg arg;

#ifdef CONFIG_TCP_MD5SIG

	struct tcp_md5sig_key *key;

	struct tcp_md5sig_key *key = NULL;

	const __u8 *hash_location = NULL;

	unsigned char newhash[16];

	int genhash;
@@ -627,7 +627,10 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);

#ifdef CONFIG_TCP_MD5SIG

	hash_location = tcp_parse_md5sig_option(th);

	if (!sk && hash_location) {

	if (sk) {

		key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)

					&ip_hdr(skb)->saddr, AF_INET);

	} else if (hash_location) {

		/*

		 * active side is lost. Try to find listening socket through

		 * source port, and then find md5 key through listening socket.
@@ -651,10 +654,6 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
		genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);

		if (genhash || memcmp(hash_location, newhash, 16) != 0)

			goto release_sk1;

	} else {

		key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *)

					     &ip_hdr(skb)->saddr,

					     AF_INET) : NULL;

	}



	if (key) {

net/ipv6/tcp_ipv6.c

+3 −3
Original line number Diff line number Diff line
@@ -854,7 +854,9 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 


#ifdef CONFIG_TCP_MD5SIG

	hash_location = tcp_parse_md5sig_option(th);

	if (!sk && hash_location) {

	if (sk) {

		key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);

	} else if (hash_location) {

		/*

		 * active side is lost. Try to find listening socket through

		 * source port, and then find md5 key through listening socket.
@@ -877,8 +879,6 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 
		genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);

		if (genhash || memcmp(hash_location, newhash, 16) != 0)

			goto release_sk1;

	} else {

		key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;

	}

#endif

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