[PATCH 4.19 31/45] net/smc: do not schedule tx_work in SMC_CLOSED state

From: Greg Kroah-Hartman
Date: Thu Aug 08 2019 - 15:13:49 EST


From: Ursula Braun <ubraun@xxxxxxxxxxxxx>

[ Upstream commit f9cedf1a9b1cdcfb0c52edb391d01771e43994a4 ]

The setsockopts options TCP_NODELAY and TCP_CORK may schedule the
tx worker. Make sure the socket is not yet moved into SMC_CLOSED
state (for instance by a shutdown SHUT_RDWR call).

Reported-by: syzbot+92209502e7aab127c75f@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+b972214bb803a343f4fe@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 01d2f7e2cdd31 ("net/smc: sockopts TCP_NODELAY and TCP_CORK")
Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/smc/af_smc.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1680,14 +1680,18 @@ static int smc_setsockopt(struct socket
}
break;
case TCP_NODELAY:
- if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
+ if (sk->sk_state != SMC_INIT &&
+ sk->sk_state != SMC_LISTEN &&
+ sk->sk_state != SMC_CLOSED) {
if (val && !smc->use_fallback)
mod_delayed_work(system_wq, &smc->conn.tx_work,
0);
}
break;
case TCP_CORK:
- if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
+ if (sk->sk_state != SMC_INIT &&
+ sk->sk_state != SMC_LISTEN &&
+ sk->sk_state != SMC_CLOSED) {
if (!val && !smc->use_fallback)
mod_delayed_work(system_wq, &smc->conn.tx_work,
0);