net: ipv6: keep sk status consistent after datagram connect failure (2f987a76) · Commits · 戴 / test

On unsuccesful ip6_datagram_connect(), if the failure is caused by ip6_datagram_dst_update(), the sk peer information are cleared, but the sk->sk_state is preserved. If the socket was already in an established status, the overall sk status is inconsistent and fouls later checks in datagram code. Fix this saving the old peer information and restoring them in case of failure. This also aligns ipv6 datagram connect() behavior with ipv4. v1 -> v2: - added missing Fixes tag Fixes: ("net: ipv6: reset daddr and dport in sk if connect() fails") Signed-off-by:

Paolo Abeni <pabeni@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv6/datagram.c

+14 −7

Original line number	Diff line number	Diff line
		@@ -146,10 +146,12 @@ int __ip6_datagram_connect(struct sock sk, struct sockaddr uaddr,
		struct sockaddr_in6 usin = (struct sockaddr_in6 ) uaddr;
		struct inet_sock *inet = inet_sk(sk);
		struct ipv6_pinfo *np = inet6_sk(sk);
		struct in6_addr *daddr;
		struct in6_addr *daddr, old_daddr;
		__be32 fl6_flowlabel = 0;
		__be32 old_fl6_flowlabel;
		__be32 old_dport;
		int addr_type;
		int err;
		__be32 fl6_flowlabel = 0;

		if (usin->sin6_family == AF_INET) {
		if (__ipv6_only_sock(sk))
		@@ -238,9 +240,13 @@ ipv4_connected:
		}
		}

		/* save the current peer information before updating it */
		old_daddr = sk->sk_v6_daddr;
		old_fl6_flowlabel = np->flow_label;
		old_dport = inet->inet_dport;

		sk->sk_v6_daddr = *daddr;
		np->flow_label = fl6_flowlabel;

		inet->inet_dport = usin->sin6_port;

		/*
		@@ -250,11 +256,12 @@ ipv4_connected:

		err = ip6_datagram_dst_update(sk, true);
		if (err) {
		/* Reset daddr and dport so that udp_v6_early_demux()
		* fails to find this socket
		/* Restore the socket peer info, to keep it consistent with
		* the old socket state
		*/
		memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
		inet->inet_dport = 0;
		sk->sk_v6_daddr = old_daddr;
		np->flow_label = old_fl6_flowlabel;
		inet->inet_dport = old_dport;
		goto out;
		}

Admin message