[PATCH 5.15 376/667] net/smc: postpone sk_refcnt increment in connect()

[Greg Kroah-Hartman]

From: liuyacan <liuyacan@xxxxxxxxxxxxxxxx>

[ Upstream commit 75c1edf23b95a9c66923d9269d8e86e4dbde151f ]

Same trigger condition as commit 86434744. When setsockopt runs
in parallel to a connect(), and switch the socket into fallback
mode. Then the sk_refcnt is incremented in smc_connect(), but
its state stay in SMC_INIT (NOT SMC_ACTIVE). This cause the
corresponding sk_refcnt decrement in __smc_release() will not be
performed.

Fixes: 86434744fedf ("net/smc: add fallback check to connect()")
Signed-off-by: liuyacan <liuyacan@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/smc/af_smc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fb801c249d92..2ddd7b34b4ce 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1283,9 +1283,9 @@ static int smc_connect(struct socket *sock, struct sockaddr *addr,
 	if (rc && rc != -EINPROGRESS)
 		goto out;
 
-	sock_hold(&smc->sk); /* sock put in passive closing */
 	if (smc->use_fallback)
 		goto out;
+	sock_hold(&smc->sk); /* sock put in passive closing */
 	if (flags & O_NONBLOCK) {
 		if (queue_work(smc_hs_wq, &smc->connect_work))
 			smc->connect_nonblock = 1;
-- 
2.35.1