net/smc: allow sysctl rmem and wmem defaults for servers

Without setsockopt SO_SNDBUF and SO_RCVBUF settings, the sysctl
defaults net.ipv4.tcp_wmem and net.ipv4.tcp_rmem should be the base
for the sizes of the SMC sndbuf and rcvbuf. Any TCP buffer size
optimizations for servers should be ignored.

Signed-off-by: Ursula Braun <>
Signed-off-by: David S. Miller <>
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 1288c7b..0ee7721 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1122,6 +1122,8 @@
 		sock_hold(lsk); /* sock_put in smc_listen_work */
 		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
+		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
+		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
 		sock_hold(&new_smc->sk); /* sock_put in passive closing */
 		if (!schedule_work(&new_smc->smc_listen_work))