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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Taehee Yoo <ap420073@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.17 433/772] amt: fix gateway mode stuck
Date:   Tue,  7 Jun 2022 19:00:25 +0200
Message-Id: <20220607165001.763306841@linuxfoundation.org>
In-Reply-To: <20220607164948.980838585@linuxfoundation.org>
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From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 937956ba404e70a765ca5aa39d3d7564d86a8872 ]

If a gateway can not receive any response to requests from a relay,
gateway resets status from SENT_REQUEST to INIT and variable about a
relay as well. And then it should start the full establish step
from sending a discovery message and receiving advertisement message.
But, after failure in amt_req_work() it continues sending a request
message step with flushed(invalid) relay information and sets SENT_REQUEST.
So, a gateway can't be established with a relay.
In order to avoid this situation, it stops sending the request message
step if it fails.

Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/amt.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index f1a36d7e2151..96a2f6a505c3 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -943,7 +943,7 @@ static void amt_req_work(struct work_struct *work)
 	if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
 		goto out;
 
-	if (amt->req_cnt++ > AMT_MAX_REQ_COUNT) {
+	if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
 		netdev_dbg(amt->dev, "Gateway is not ready");
 		amt->qi = AMT_INIT_REQ_TIMEOUT;
 		amt->ready4 = false;
@@ -951,13 +951,15 @@ static void amt_req_work(struct work_struct *work)
 		amt->remote_ip = 0;
 		__amt_update_gw_status(amt, AMT_STATUS_INIT, false);
 		amt->req_cnt = 0;
+		goto out;
 	}
 	spin_unlock_bh(&amt->lock);
 
 	amt_send_request(amt, false);
 	amt_send_request(amt, true);
-	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
 	spin_lock_bh(&amt->lock);
+	__amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
+	amt->req_cnt++;
 out:
 	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
-- 
2.35.1