[PATCH 6.18.y] mptcp: pm: reset retrans_time when ADD_ADDR entry is reused

[Sasha Levin <sashal@kernel.org>]

From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>

[ Upstream commit f968190c0b42ea2004dc1426359a53ec365a7a37 ]

When an ADD_ADDR entry is reused, the timer is re-armed, because the
goal is to re-announce an ADD_ADDR, and eventually retransmit it if
needed.

In this case, the retransmission counter should be reset as well, so the
re-announced address gets its retransmissions back instead of relying on
what was left before, and possibly not being able to retransmit it.

Fixes: 304ab97f4c7c ("mptcp: allow ADD_ADDR reissuance by userspace PMs")
Cc: stable@vger.kernel.org
Link: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260803-net-mptcp-misc-fixes-7-2-rc6-v2-0-b8f496d71664%40kernel.org?part=4
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260908-net-mptcp-misc-fixes-7-3-rc1-v2-9-df1de70348b6@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mptcp/pm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index a67efcfa26f14..01c91edbee1e7 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -461,10 +461,10 @@ bool mptcp_pm_announced_alloc(struct mptcp_sock *msk,
 
 	add_entry->addr = *addr;
 	add_entry->sock = msk;
-	add_entry->retrans_times = 0;
 
 	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 reset_timer:
+	add_entry->retrans_times = 0;
 	add_entry->timer_done = false;
 	timeout = mptcp_adjust_add_addr_timeout(msk);
 	if (timeout)
-- 
2.53.0