This is a note to let you know that I've just added the patch titled

net: ipv6: keep sk status consistent after datagram connect failure

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: net-ipv6-keep-sk-status-consistent-after-datagram-connect-failure.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Mar 28 18:37:51 CEST 2018

From: Paolo Abeni pabeni@redhat.com Date: Mon, 12 Mar 2018 14:54:23 +0100 Subject: net: ipv6: keep sk status consistent after datagram connect failure

From: Paolo Abeni pabeni@redhat.com

[ Upstream commit 2f987a76a97773beafbc615b9c4d8fe79129a7f4 ]

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: 85cb73ff9b74 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/datagram.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)

--- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -146,10 +146,12 @@ int __ip6_datagram_connect(struct sock * 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)) @@ -239,9 +241,13 @@ 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;

/* @@ -251,11 +257,12 @@ 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; }

Patches currently in stable-queue which might be from pabeni@redhat.com are

queue-4.15/ipv6-old_dport-should-be-a-__be16-in-__ip6_datagram_connect.patch queue-4.15/net-ipv6-keep-sk-status-consistent-after-datagram-connect-failure.patch