lkml.org 
[lkml]   [2019]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.2 48/56] net/smc: avoid fallback in case of non-blocking connect
Date
From: Ursula Braun <ubraun@linux.ibm.com>

[ Upstream commit cd2063604ea6a8c2683b4eb9b5f4c4da74592d87 ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/smc/af_smc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -253,7 +253,7 @@ static int smc_bind(struct socket *sock,

/* 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;
@@ -1399,7 +1399,8 @@ static int smc_listen(struct socket *soc
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;
@@ -1527,7 +1528,7 @@ static int smc_sendmsg(struct socket *so
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 {

\
 
 \ /
  Last update: 2019-08-08 21:26    [W:0.273 / U:5.848 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site