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 0137a3c7c2ea3f9df8ebfc65d78b4ba712a187bb # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024082608-cornmeal-stoop-7021@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

0137a3c7c2ea ("mptcp: pm: check add_addr_accept_max before accepting new ADD_ADDR") 1c1f72137598 ("mptcp: pm: only decrement add_addr_accepted for MPJ req") 322ea3778965 ("mptcp: pm: only mark 'subflow' endp as available") f448451aa62d ("mptcp: pm: remove mptcp_pm_remove_subflow()") ef34a6ea0cab ("mptcp: pm: re-using ID of unused flushed subflows") edd8b5d868a4 ("mptcp: pm: re-using ID of unused removed subflows") 4b317e0eb287 ("mptcp: fix NL PM announced address accounting") 6a09788c1a66 ("mptcp: pm: inc RmAddr MIB counter once per RM_ADDR ID") 9bbec87ecfe8 ("mptcp: unify pm get_local_id interfaces") dc886bce753c ("mptcp: export local_address") 8b1c94da1e48 ("mptcp: only send RM_ADDR in nl_cmd_remove") 3ad14f54bd74 ("mptcp: more accurate MPC endpoint tracking") c157bbe776b7 ("mptcp: allow the in kernel PM to set MPC subflow priority") 843b5e75efff ("mptcp: fix local endpoint accounting") d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE") 9ab4807c84a4 ("mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE") 982f17ba1a25 ("mptcp: netlink: split mptcp_pm_parse_addr into two functions") 8b20137012d9 ("mptcp: read attributes of addr entries managed by userspace PMs") 4638de5aefe5 ("mptcp: handle local addrs announced by userspace PMs") 4d25247d3ae4 ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs")

thanks,

greg k-h

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

From 0137a3c7c2ea3f9df8ebfc65d78b4ba712a187bb Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" matttbe@kernel.org Date: Mon, 19 Aug 2024 21:45:28 +0200 Subject: [PATCH] mptcp: pm: check add_addr_accept_max before accepting new ADD_ADDR

The limits might have changed in between, it is best to check them before accepting new ADD_ADDR.

Fixes: d0876b2284cf ("mptcp: add the incoming RM_ADDR support") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://patch.msgid.link/20240819-net-mptcp-pm-reusing-id-v1-10-38035d40de5b... Signed-off-by: Jakub Kicinski kuba@kernel.org

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 882781571c7b..28a9a3726146 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -848,8 +848,8 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk, /* Note: if the subflow has been closed before, this * add_addr_accepted counter will not be decremented. */ - msk->pm.add_addr_accepted--; - WRITE_ONCE(msk->pm.accept_addr, true); + if (--msk->pm.add_addr_accepted < mptcp_pm_get_add_addr_accept_max(msk)) + WRITE_ONCE(msk->pm.accept_addr, true); } } }