From d4c67071f481145a84591b97abc309c772d68dfb Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Wed, 31 Jul 2024 13:05:54 +0200 Subject: [PATCH] mptcp: pm: deny endp with signal + subflow + port commit 8af1f11865f259c882cce71d32f85ee9004e2660 upstream. As mentioned in the 'Fixes' commit, the port flag is only supported by the 'signal' flag, and not by the 'subflow' one. Then if both the 'signal' and 'subflow' flags are set, the problem is the same: the feature cannot work with the 'subflow' flag. Technically, if both the 'signal' and 'subflow' flags are set, it will be possible to create the listening socket, but not to establish a subflow using this source port. So better to explicitly deny it, not to create some confusions because the expected behaviour is not possible. Fixes: 09f12c3ab7a5 ("mptcp: allow to use port and non-signal in set_flags") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20240731-upstream-net-20240731-mptcp-endp-subflow-signal-v1-2-c8a9b036493b@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index ea06ef80c60f..be4be3bcefc7 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1359,8 +1359,8 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) if (ret < 0) return ret; - if (addr.addr.port && !(addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) { - GENL_SET_ERR_MSG(info, "flags must have signal when using port"); + if (addr.addr.port && !address_use_port(&addr)) { + GENL_SET_ERR_MSG(info, "flags must have signal and not subflow when using port"); return -EINVAL; }