Subject: [PATCH AUTOSEL 5.13 184/219] mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other

From: Sasha Levin <[email-masked]>
Date: Thu, 9 Sep 2021 07:46:00 -0400

From: Yonglong Li <[email-masked]>

[ Upstream commit 119c022096f5805680c79dfa74e15044c289856d ]

ADD_ADDR shares pm.addr_signal with RM_ADDR, so after RM_ADDR/ADD_ADDR
has done, we should not clean ADD_ADDR/RM_ADDR's addr_signal.

Co-developed-by: Geliang Tang <[email-masked]>
Signed-off-by: Geliang Tang <[email-masked]>
Signed-off-by: Yonglong Li <[email-masked]>
Signed-off-by: Mat Martineau <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 net/mptcp/pm.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 9d00fa6d22e9..feecc3485c68 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -253,6 +253,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			      struct mptcp_addr_info *saddr, bool *echo, bool *port)
 {
 	int ret = false;
+	u8 add_addr;
 
 	spin_lock_bh(&msk->pm.lock);
 
@@ -267,7 +268,11 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 		goto out_unlock;
 
 	*saddr = msk->pm.local;
-	WRITE_ONCE(msk->pm.addr_signal, 0);
+	if (*echo)
+		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO);
+	else
+		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL);
+	WRITE_ONCE(msk->pm.addr_signal, add_addr);
 	ret = true;
 
 out_unlock:
@@ -279,6 +284,7 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 			     struct mptcp_rm_list *rm_list)
 {
 	int ret = false, len;
+	u8 rm_addr;
 
 	spin_lock_bh(&msk->pm.lock);
 
@@ -286,16 +292,17 @@ bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
 	if (!mptcp_pm_should_rm_signal(msk))
 		goto out_unlock;
 
+	rm_addr = msk->pm.addr_signal & ~BIT(MPTCP_RM_ADDR_SIGNAL);
 	len = mptcp_rm_addr_len(&msk->pm.rm_list_tx);
 	if (len < 0) {
-		WRITE_ONCE(msk->pm.addr_signal, 0);
+		WRITE_ONCE(msk->pm.addr_signal, rm_addr);
 		goto out_unlock;
 	}
 	if (remaining < len)
 		goto out_unlock;
 
 	*rm_list = msk->pm.rm_list_tx;
-	WRITE_ONCE(msk->pm.addr_signal, 0);
+	WRITE_ONCE(msk->pm.addr_signal, rm_addr);
 	ret = true;
 
 out_unlock:
-- 
2.30.2