[PATCH 5.15.y] mptcp: pm: only set request_bkup flag when sending MP_PRIO

["Matthieu Baerts (NGI0)" <matttbe@kernel.org>]

commit 4258b94831bb7ff28ab80e3c8d94db37db930728 upstream.

The 'backup' flag from mptcp_subflow_context structure is supposed to be
set only when the other peer flagged a subflow as backup, not the
opposite.

Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflicts in pm_netlink.c, because the commit f5360e9b314c ("mptcp:
  introduce and use mptcp_pm_send_ack()") is not in this version. This
  code is in mptcp_pm_nl_mp_prio_send_ack() instead of in a dedicated
  helper. The same modification can be applied there. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 net/mptcp/pm_netlink.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 1d64c9fed39e..67ece399ef60 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -699,7 +699,6 @@ int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 
 		if (subflow->backup != bkup)
 			msk->last_snd = NULL;
-		subflow->backup = bkup;
 		subflow->send_mp_prio = 1;
 		subflow->request_bkup = bkup;
 		__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIOTX);
-- 
2.45.2