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

liuyacan
2022-05-23T03:24:58Z

From: liuyacan <liuyacan@corp.netease.com>

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.

Signed-off-by: liuyacan <liuyacan@corp.netease.com>
Fixes: 86434744 ("net/smc: add fallback check to connect()")
---
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 fce16b9d6..45a24d242 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1564,9 +1564,9 @@ 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;
--
2.20.1