The patch below does not apply to the 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 4b317e0eb287bd30a1b329513531157c25e8b692 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024080705-poise-profile-662a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

4b317e0eb287 ("mptcp: fix NL PM announced address accounting") 6fa0174a7c86 ("mptcp: more careful RM_ADDR generation") 7d9bf018f907 ("selftests: mptcp: update output info of chk_rm_nr") 327b9a94e2a8 ("selftests: mptcp: more stable join tests-cases")

thanks,

greg k-h

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

From 4b317e0eb287bd30a1b329513531157c25e8b692 Mon Sep 17 00:00:00 2001 From: Paolo Abeni pabeni@redhat.com Date: Sat, 27 Jul 2024 11:04:00 +0200 Subject: [PATCH] mptcp: fix NL PM announced address accounting

Currently the per connection announced address counter is never decreased. As a consequence, after connection establishment, if the NL PM deletes an endpoint and adds a new/different one, no additional subflow is created for the new endpoint even if the current limits allow that.

Address the issue properly updating the signaled address counter every time the NL PM removes such addresses.

Fixes: 01cacb00b35c ("mptcp: add netlink-based PM") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: David S. Miller davem@davemloft.net

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index b399f2b7a369..f65831de5c1a 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1401,6 +1401,7 @@ static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk, ret = remove_anno_list_by_saddr(msk, addr); if (ret || force) { spin_lock_bh(&msk->pm.lock); + msk->pm.add_addr_signaled -= ret; mptcp_pm_remove_addr(msk, &list); spin_unlock_bh(&msk->pm.lock); } @@ -1565,17 +1566,18 @@ static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk, struct mptcp_pm_addr_entry *entry;

list_for_each_entry(entry, rm_list, list) { - if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) && - slist.nr < MPTCP_RM_IDS_MAX) + if (slist.nr < MPTCP_RM_IDS_MAX && + lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) slist.ids[slist.nr++] = entry->addr.id;

- if (remove_anno_list_by_saddr(msk, &entry->addr) && - alist.nr < MPTCP_RM_IDS_MAX) + if (alist.nr < MPTCP_RM_IDS_MAX && + remove_anno_list_by_saddr(msk, &entry->addr)) alist.ids[alist.nr++] = entry->addr.id; }

if (alist.nr) { spin_lock_bh(&msk->pm.lock); + msk->pm.add_addr_signaled -= alist.nr; mptcp_pm_remove_addr(msk, &alist); spin_unlock_bh(&msk->pm.lock); }