This is a note to let you know that I've just added the patch titled udp: preserve the connected status if only UDP cmsg to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: udp-preserve-the-connected-status-if-only-udp-cmsg.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 680d11f6e5427b6af1321932286722d24a8b16c1 Mon Sep 17 00:00:00 2001 From: Yick Xie <yick.xie@xxxxxxxxx> Date: Fri, 19 Apr 2024 01:06:10 +0800 Subject: udp: preserve the connected status if only UDP cmsg From: Yick Xie <yick.xie@xxxxxxxxx> commit 680d11f6e5427b6af1321932286722d24a8b16c1 upstream. If "udp_cmsg_send()" returned 0 (i.e. only UDP cmsg), "connected" should not be set to 0. Otherwise it stops the connected socket from using the cached route. Fixes: 2e8de8576343 ("udp: add gso segment cmsg") Signed-off-by: Yick Xie <yick.xie@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240418170610.867084-1-yick.xie@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Yick Xie <yick.xie@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/udp.c | 5 +++-- net/ipv6/udp.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1001,16 +1001,17 @@ int udp_sendmsg(struct sock *sk, struct if (msg->msg_controllen) { err = udp_cmsg_send(sk, msg, &ipc.gso_size); - if (err > 0) + if (err > 0) { err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6); + connected = 0; + } if (unlikely(err < 0)) { kfree(ipc.opt); return err; } if (ipc.opt) free = 1; - connected = 0; } if (!ipc.opt) { struct ip_options_rcu *inet_opt; --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1324,9 +1324,11 @@ do_udp_sendmsg: ipc6.opt = opt; err = udp_cmsg_send(sk, msg, &ipc6.gso_size); - if (err > 0) + if (err > 0) { err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); + connected = false; + } if (err < 0) { fl6_sock_release(flowlabel); return err; @@ -1338,7 +1340,6 @@ do_udp_sendmsg: } if (!(opt->opt_nflen|opt->opt_flen)) opt = NULL; - connected = false; } if (!opt) { opt = txopt_get(np); Patches currently in stable-queue which might be from yick.xie@xxxxxxxxx are queue-4.19/udp-preserve-the-connected-status-if-only-udp-cmsg.patch