[PATCH 5.10 042/103] net/smc: fix workqueue leaked lock in smc_conn_abort_work

From: Greg Kroah-Hartman
Date: Mon Sep 27 2021 - 13:11:53 EST

From: Karsten Graul <kgraul@xxxxxxxxxxxxx>

[ 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() 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@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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)
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 */