The patch below does not apply to the 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x e2f4ac7bab2205d3c4dd9464e6ffd82502177c51 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025041757-treble-debatable-db2c@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From e2f4ac7bab2205d3c4dd9464e6ffd82502177c51 Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" matttbe@kernel.org Date: Fri, 14 Mar 2025 21:11:33 +0100 Subject: [PATCH] mptcp: sockopt: fix getting freebind & transparent

When adding a socket option support in MPTCP, both the get and set parts are supposed to be implemented.

IP(V6)_FREEBIND and IP(V6)_TRANSPARENT support for the setsockopt part has been added a while ago, but it looks like the get part got forgotten. It should have been present as a way to verify a setting has been set as expected, and not to act differently from TCP or any other socket types.

Everything was in place to expose it, just the last step was missing. Only new code is added to cover these specific getsockopt(), that seems safe.

Fixes: c9406a23c116 ("mptcp: sockopt: add SOL_IP freebind & transparent options") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250314-net-mptcp-fix-data-stream-corr-sockopt-v1-... Signed-off-by: Paolo Abeni pabeni@redhat.com

diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 4b99eb796855..3caa0a9d3b38 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -1419,6 +1419,12 @@ static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, switch (optname) { case IP_TOS: return mptcp_put_int_option(msk, optval, optlen, READ_ONCE(inet_sk(sk)->tos)); + case IP_FREEBIND: + return mptcp_put_int_option(msk, optval, optlen, + inet_test_bit(FREEBIND, sk)); + case IP_TRANSPARENT: + return mptcp_put_int_option(msk, optval, optlen, + inet_test_bit(TRANSPARENT, sk)); case IP_BIND_ADDRESS_NO_PORT: return mptcp_put_int_option(msk, optval, optlen, inet_test_bit(BIND_ADDRESS_NO_PORT, sk)); @@ -1439,6 +1445,12 @@ static int mptcp_getsockopt_v6(struct mptcp_sock *msk, int optname, case IPV6_V6ONLY: return mptcp_put_int_option(msk, optval, optlen, sk->sk_ipv6only); + case IPV6_TRANSPARENT: + return mptcp_put_int_option(msk, optval, optlen, + inet_test_bit(TRANSPARENT, sk)); + case IPV6_FREEBIND: + return mptcp_put_int_option(msk, optval, optlen, + inet_test_bit(FREEBIND, sk)); }

return -EOPNOTSUPP;