The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 9ebb0c4b27a6158303b791b5b91e66d7665ee30e Mon Sep 17 00:00:00 2001
From: Guo DaXing <guodaxing@xxxxxxxxxx>
Date: Wed, 24 Nov 2021 13:32:38 +0100
Subject: [PATCH] net/smc: Fix loop in smc_listen
The kernel_listen function in smc_listen will fail when all the available
ports are occupied. At this point smc->clcsock->sk->sk_data_ready has
been changed to smc_clcsock_data_ready. When we call smc_listen again,
now both smc->clcsock->sk->sk_data_ready and smc->clcsk_data_ready point
to the smc_clcsock_data_ready function.
The smc_clcsock_data_ready() function calls lsmc->clcsk_data_ready which
now points to itself resulting in an infinite loop.
This patch restores smc->clcsock->sk->sk_data_ready with the old value.
Fixes: a60a2b1e0af1 ("net/smc: reduce active tcp_listen workers")
Signed-off-by: Guo DaXing <guodaxing@xxxxxxxxxx>
Acked-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx>
Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 2692cba5a7b6..4b62c925a13e 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2134,8 +2134,10 @@ static int smc_listen(struct socket *sock, int backlog)
smc->clcsock->sk->sk_user_data =
(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
rc = kernel_listen(smc->clcsock, backlog);
- if (rc)
+ if (rc) {
+ smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
goto out;
+ }
sk->sk_max_ack_backlog = backlog;
sk->sk_ack_backlog = 0;
sk->sk_state = SMC_LISTEN;
