The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 680d11f6e5427b6af1321932286722d24a8b16c1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024042920-overcoat-cannot-efc1@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

680d11f6e542 ("udp: preserve the connected status if only UDP cmsg") 5298953e742d ("udp6: don't make extra copies of iflow") 42dcfd850e51 ("udp6: allow SO_MARK ctrl msg to affect routing") 3df98d79215a ("lsm,selinux: pass flowi_common instead of flowi to the LSM hooks") e94ee171349d ("xfrm: Use correct address family in xfrm_state_find") 5eff06902394 ("ipv4: fill fl4_icmp_{type,code} in ping_v4_sendmsg") 6abde0b24122 ("crypto/chtls: IPv6 support for inline TLS") ed52f2c608c9 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 680d11f6e5427b6af1321932286722d24a8b16c1 Mon Sep 17 00:00:00 2001 From: Yick Xie yick.xie@gmail.com Date: Fri, 19 Apr 2024 01:06:10 +0800 Subject: [PATCH] udp: preserve the connected status if only UDP cmsg

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@gmail.com Cc: stable@vger.kernel.org Reviewed-by: Willem de Bruijn willemb@google.com Link: https://lore.kernel.org/r/20240418170610.867084-1-yick.xie@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index c02bf011d4a6..420905be5f30 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1123,16 +1123,17 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)

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; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 8b1dd7f51249..1a4cccdd40c9 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1474,9 +1474,11 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 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; @@ -1488,7 +1490,6 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) } if (!(opt->opt_nflen|opt->opt_flen)) opt = NULL; - connected = false; } if (!opt) { opt = txopt_get(np);