6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> [ Upstream commit a65198136eaa15b74ee0abf73f12ef83d469a334 ] SO_KEEPALIVE support has to be set on each subflow: on each TCP socket, where sk_prot->keepalive is defined. Technically, nothing has to be done on the MPTCP socket. That's why mptcp_sol_socket_sync_intval() was called instead of mptcp_sol_socket_intval(). Except that when nothing is done on the MPTCP socket, the getsockopt(SO_KEEPALIVE), handled in net/core/sock.c:sk_getsockopt(), will not know if SO_KEEPALIVE has been set on the different subflows or not. The fix is simple: simply call mptcp_sol_socket_intval() which will end up calling net/core/sock.c:sk_setsockopt() where the SOCK_KEEPOPEN flag will be set, the one used in sk_getsockopt(). So now, getsockopt(SO_KEEPALIVE) on an MPTCP socket will return the same value as the one previously set with setsockopt(SO_KEEPALIVE). Fixes: 1b3e7ede1365 ("mptcp: setsockopt: handle SO_KEEPALIVE and SO_PRIORITY") Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> Signed-off-by: Mat Martineau <martineau@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240514011335.176158-2-martineau@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/mptcp/sockopt.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 73fdf423de44e..08b7be2b1b69e 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -181,8 +181,6 @@ static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname, switch (optname) { case SO_KEEPALIVE: - mptcp_sol_socket_sync_intval(msk, optname, val); - return 0; case SO_DEBUG: case SO_MARK: case SO_PRIORITY: -- 2.43.0