| From aa7bdffb2a79d695fde4d6225241307a3afce548 Mon Sep 17 00:00:00 2001 |
| From: Ursula Braun <ubraun@linux.ibm.com> |
| Date: Fri, 15 Nov 2019 12:39:30 +0100 |
| Subject: [PATCH] net/smc: fix fastopen for non-blocking connect() |
| |
| commit 8204df72bea1a7d83d0777add6da98a41dfbdc34 upstream. |
| |
| FASTOPEN does not work with SMC-sockets. Since SMC allows fallback to |
| TCP native during connection start, the FASTOPEN setsockopts trigger |
| this fallback, if the SMC-socket is still in state SMC_INIT. |
| But if a FASTOPEN setsockopt is called after a non-blocking connect(), |
| this is broken, and fallback does not make sense. |
| This change complements |
| commit cd2063604ea6 ("net/smc: avoid fallback in case of non-blocking connect") |
| and fixes the syzbot reported problem "WARNING in smc_unhash_sk". |
| |
| Reported-by: syzbot+8488cc4cf1c9e09b8b86@syzkaller.appspotmail.com |
| Fixes: e1bbdd570474 ("net/smc: reduce sock_put() for fallback sockets") |
| Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> |
| Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c |
| index e04414f84a87..a9f12fae156b 100644 |
| --- a/net/smc/af_smc.c |
| +++ b/net/smc/af_smc.c |
| @@ -1741,7 +1741,7 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, |
| case TCP_FASTOPEN_KEY: |
| case TCP_FASTOPEN_NO_COOKIE: |
| /* option not supported by SMC */ |
| - if (sk->sk_state == SMC_INIT) { |
| + if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) { |
| smc_switch_to_fallback(smc); |
| smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP; |
| } else { |
| -- |
| 2.7.4 |
| |
