Message ID | 20190802084750.5518-1-kgraul@linux.ibm.com |
---|---|
State | Accepted |
Delegated to: | David Miller |
Headers | show |
Series | [net] net/smc: avoid fallback in case of non-blocking connect | expand |
From: Karsten Graul <kgraul@linux.ibm.com> Date: Fri, 2 Aug 2019 10:47:50 +0200 > From: Ursula Braun <ubraun@linux.ibm.com> > > FASTOPEN is not possible with SMC. sendmsg() with msg_flag MSG_FASTOPEN > triggers a fallback to TCP if the socket is in state SMC_INIT. > But if a nonblocking connect is already started, fallback to TCP > is no longer possible, even though the socket may still be in state > SMC_INIT. > And if a nonblocking connect is already started, a listen() call > does not make sense. > > Reported-by: syzbot+bd8cc73d665590a1fcad@syzkaller.appspotmail.com > Fixes: 50717a37db032 ("net/smc: nonblocking connect rework") > Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> > Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Applied and queued up for -stable.
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index f5ea09258ab0..5b932583e407 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -263,7 +263,7 @@ static int smc_bind(struct socket *sock, struct sockaddr *uaddr, /* Check if socket is already active */ rc = -EINVAL; - if (sk->sk_state != SMC_INIT) + if (sk->sk_state != SMC_INIT || smc->connect_nonblock) goto out_rel; smc->clcsock->sk->sk_reuse = sk->sk_reuse; @@ -1390,7 +1390,8 @@ static int smc_listen(struct socket *sock, int backlog) lock_sock(sk); rc = -EINVAL; - if ((sk->sk_state != SMC_INIT) && (sk->sk_state != SMC_LISTEN)) + if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) || + smc->connect_nonblock) goto out; rc = 0; @@ -1518,7 +1519,7 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) goto out; if (msg->msg_flags & MSG_FASTOPEN) { - 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 {