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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, Karsten Graul <kgraul@linux.ibm.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 042/103] net/smc: fix workqueue leaked lock in smc_conn_abort_work
Date:   Mon, 27 Sep 2021 19:02:14 +0200
Message-Id: <20210927170227.199687390@linuxfoundation.org>
In-Reply-To: <20210927170225.702078779@linuxfoundation.org>
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From: Karsten Graul <kgraul@linux.ibm.com>

[ Upstream commit a18cee4791b1123d0a6579a7c89f4b87e48abe03 ]

The abort_work is scheduled when a connection was detected to be
out-of-sync after a link failure. The work calls smc_conn_kill(),
which calls smc_close_active_abort() and that might end up calling
smc_close_cancel_work().
smc_close_cancel_work() cancels any pending close_work and tx_work but
needs to release the sock_lock before and acquires the sock_lock again
afterwards. So when the sock_lock was NOT acquired before then it may
be held after the abort_work completes. Thats why the sock_lock is
acquired before the call to smc_conn_kill() in __smc_lgr_terminate(),
but this is missing in smc_conn_abort_work().

Fix that by acquiring the sock_lock first and release it after the
call to smc_conn_kill().

Fixes: b286a0651e44 ("net/smc: handle incoming CDC validation message")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/smc/smc_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index af96f813c075..c491dd8e67cd 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1089,7 +1089,9 @@ static void smc_conn_abort_work(struct work_struct *work)
 						   abort_work);
 	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 
+	lock_sock(&smc->sk);
 	smc_conn_kill(conn, true);
+	release_sock(&smc->sk);
 	sock_put(&smc->sk); /* sock_hold done by schedulers of abort_work */
 }
 
-- 
2.33.0