From caa21e19e08d7a1445116a93f7ab4e187ebbbadb Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Wed, 8 Aug 2018 14:13:19 +0200 Subject: net/smc: no shutdown in state SMC_LISTEN Invoking shutdown for a socket in state SMC_LISTEN does not make sense. Nevertheless programs like syzbot fuzzing the kernel may try to do this. For SMC this means a socket refcounting problem. This patch makes sure a shutdown call for an SMC socket in state SMC_LISTEN simply returns with -ENOTCONN. Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 05e4ffe5aabd..1288c7bf40d5 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1397,8 +1397,7 @@ static int smc_shutdown(struct socket *sock, int how) lock_sock(sk); rc = -ENOTCONN; - if ((sk->sk_state != SMC_LISTEN) && - (sk->sk_state != SMC_ACTIVE) && + if ((sk->sk_state != SMC_ACTIVE) && (sk->sk_state != SMC_PEERCLOSEWAIT1) && (sk->sk_state != SMC_PEERCLOSEWAIT2) && (sk->sk_state != SMC_APPCLOSEWAIT1) && -- cgit v1.2.3 From bd58c7e0860f54710907903ed6daff699d1fc5b9 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Wed, 8 Aug 2018 14:13:20 +0200 Subject: 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 --- net/smc/af_smc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/smc') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 1288c7bf40d5..0ee7721afbe5 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1122,6 +1122,8 @@ static void smc_tcp_listen_work(struct work_struct *work) sock_hold(lsk); /* sock_put in smc_listen_work */ INIT_WORK(&new_smc->smc_listen_work, smc_listen_work); smc_copy_sock_settings_to_smc(new_smc); + 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)) sock_put(&new_smc->sk); -- cgit v1.2.3 From 7311d665ca68907b9c43d6d1021f816f9a7bbd57 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Wed, 8 Aug 2018 14:13:21 +0200 Subject: net/smc: move sock lock in smc_ioctl() When an SMC socket is connecting it is decided whether fallback to TCP is needed. To avoid races between connect and ioctl move the sock lock before the use_fallback check. Reported-by: syzbot+5b2cece1a8ecb2ca77d8@syzkaller.appspotmail.com Reported-by: syzbot+19557374321ca3710990@syzkaller.appspotmail.com Fixes: 1992d99882af ("net/smc: take sock lock in smc_ioctl()") Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'net/smc') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 0ee7721afbe5..e7de5f282722 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1522,12 +1522,16 @@ static int smc_ioctl(struct socket *sock, unsigned int cmd, smc = smc_sk(sock->sk); conn = &smc->conn; + lock_sock(&smc->sk); if (smc->use_fallback) { - if (!smc->clcsock) + if (!smc->clcsock) { + release_sock(&smc->sk); return -EBADF; - return smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg); + } + answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg); + release_sock(&smc->sk); + return answ; } - lock_sock(&smc->sk); switch (cmd) { case SIOCINQ: /* same as FIONREAD */ if (smc->sk.sk_state == SMC_LISTEN) { -- cgit v1.2.3