[PATCH 6.12.y 0/2] mptcp: fix recent failed backports (20250822)

[PATCH 6.12.y 0/2] mptcp: fix recent failed backports (20250822)

[Matthieu Baerts (NGI0)]

Greg recently reported the following patches could not be applied
without conflicts in this tree:

 - 5d13349472ac ("mptcp: remove duplicate sk_reset_timer call")
 - f5ce0714623c ("mptcp: disable add_addr retransmission when timeout is 0")

Conflicts have been resolved, and documented in each patch.

Geliang Tang (2):
  mptcp: remove duplicate sk_reset_timer call
  mptcp: disable add_addr retransmission when timeout is 0

 Documentation/networking/mptcp-sysctl.rst |  2 ++
 net/mptcp/pm_netlink.c                    | 18 ++++++++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

-- 
2.50.0

[PATCH 6.12.y 1/2] mptcp: remove duplicate sk_reset_timer call

[Matthieu Baerts (NGI0)]

From: Geliang Tang <tanggeliang@kylinos.cn>

commit 5d13349472ac8abcbcb94407969aa0fdc2e1f1be upstream.

sk_reset_timer() was called twice in mptcp_pm_alloc_anno_list.

Simplify the code by using a 'goto' statement to eliminate the
duplication.

Note that this is not a fix, but it will help backporting the following
patch. The same "Fixes" tag has been added for this reason.

Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout")
Cc: stable@vger.kernel.org
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-4-521fe9957892@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Before commit e4c28e3d5c09 ("mptcp: pm: move generic PM helpers to
  pm.c"), mptcp_pm_alloc_anno_list() was in pm_netlink.c. The same patch
  can be applied there without conflicts. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm_netlink.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 4f65e8abf343..46f5f960472e 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -372,9 +372,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 		if (WARN_ON_ONCE(mptcp_pm_is_kernel(msk)))
 			return false;
 
-		sk_reset_timer(sk, &add_entry->add_timer,
-			       jiffies + mptcp_get_add_addr_timeout(net));
-		return true;
+		goto reset_timer;
 	}
 
 	add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
@@ -388,6 +386,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 	add_entry->retrans_times = 0;
 
 	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
+reset_timer:
 	sk_reset_timer(sk, &add_entry->add_timer,
 		       jiffies + mptcp_get_add_addr_timeout(net));
 
-- 
2.50.0

[PATCH 6.12.y 2/2] mptcp: disable add_addr retransmission when timeout is 0

[Matthieu Baerts (NGI0)]

From: Geliang Tang <tanggeliang@kylinos.cn>

commit f5ce0714623cffd00bf2a83e890d09c609b7f50a upstream.

When add_addr_timeout was set to 0, this caused the ADD_ADDR to be
retransmitted immediately, which looks like a buggy behaviour. Instead,
interpret 0 as "no retransmissions needed".

The documentation is updated to explicitly state that setting the timeout
to 0 disables retransmission.

Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout")
Cc: stable@vger.kernel.org
Suggested-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe9957892@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Before commit e4c28e3d5c09 ("mptcp: pm: move generic PM helpers to
  pm.c"), mptcp_pm_alloc_anno_list() was in pm_netlink.c. The same patch
  can be applied there without conflicts. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 Documentation/networking/mptcp-sysctl.rst |  2 ++
 net/mptcp/pm_netlink.c                    | 13 ++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst
index 95598c21fc8e..09be0e68b9af 100644
--- a/Documentation/networking/mptcp-sysctl.rst
+++ b/Documentation/networking/mptcp-sysctl.rst
@@ -12,6 +12,8 @@ add_addr_timeout - INTEGER (seconds)
 	resent to an MPTCP peer that has not acknowledged a previous
 	ADD_ADDR message.
 
+	Do not retransmit if set to 0.
+
 	The default value matches TCP_RTO_MAX. This is a per-namespace
 	sysctl.
 
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 46f5f960472e..b763729b85e0 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -293,6 +293,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 	struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 	struct mptcp_sock *msk = entry->sock;
 	struct sock *sk = (struct sock *)msk;
+	unsigned int timeout;
 
 	pr_debug("msk=%p\n", msk);
 
@@ -310,6 +311,10 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 		goto out;
 	}
 
+	timeout = mptcp_get_add_addr_timeout(sock_net(sk));
+	if (!timeout)
+		goto out;
+
 	spin_lock_bh(&msk->pm.lock);
 
 	if (!mptcp_pm_should_add_signal_addr(msk)) {
@@ -321,7 +326,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
 
 	if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 		sk_reset_timer(sk, timer,
-			       jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
+			       jiffies + timeout);
 
 	spin_unlock_bh(&msk->pm.lock);
 
@@ -363,6 +368,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 	struct mptcp_pm_add_entry *add_entry = NULL;
 	struct sock *sk = (struct sock *)msk;
 	struct net *net = sock_net(sk);
+	unsigned int timeout;
 
 	lockdep_assert_held(&msk->pm.lock);
 
@@ -387,8 +393,9 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 
 	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 reset_timer:
-	sk_reset_timer(sk, &add_entry->add_timer,
-		       jiffies + mptcp_get_add_addr_timeout(net));
+	timeout = mptcp_get_add_addr_timeout(net);
+	if (timeout)
+		sk_reset_timer(sk, &add_entry->add_timer, jiffies + timeout);
 
 	return true;
 }
-- 
2.50.0