netdev - [PATCH net 2/2] net/smc: fix 'workqueue leaked lock' in smc_conn_abort

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210920191815.2919121-3-kgraul@linux.ibm.com>
Date:   Mon, 20 Sep 2021 21:18:15 +0200
From:   Karsten Graul <kgraul@...ux.ibm.com>
To:     David Miller <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>
Cc:     netdev@...r.kernel.org, linux-s390@...r.kernel.org,
        Heiko Carstens <hca@...ux.ibm.com>,
        Guvenc Gulce <guvenc@...ux.ibm.com>,
        Julian Wiedmann <jwi@...ux.ibm.com>
Subject: [PATCH net 2/2] net/smc: fix 'workqueue leaked lock' in smc_conn_abort_work

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@...ux.ibm.com>
---
 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 af227b65669e..8280c938be80 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1474,7 +1474,9 @@ 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 */
 }

-- 
2.25.1