From 9f1c50cf39167ff71dc5953a3234f3f6eeb8fcb5 Mon Sep 17 00:00:00 2001 From: "D. Wythe" Date: Thu, 24 Feb 2022 23:26:19 +0800 Subject: net/smc: fix connection leak There's a potential leak issue under following execution sequence : smc_release smc_connect_work if (sk->sk_state == SMC_INIT) send_clc_confirim tcp_abort(); ... sk.sk_state = SMC_ACTIVE smc_close_active switch(sk->sk_state) { ... case SMC_ACTIVE: smc_close_final() // then wait peer closed Unfortunately, tcp_abort() may discard CLC CONFIRM messages that are still in the tcp send buffer, in which case our connection token cannot be delivered to the server side, which means that we cannot get a passive close message at all. Therefore, it is impossible for the to be disconnected at all. This patch tries a very simple way to avoid this issue, once the state has changed to SMC_ACTIVE after tcp_abort(), we can actively abort the smc connection, considering that the state is SMC_INIT before tcp_abort(), abandoning the complete disconnection process should not cause too much problem. In fact, this problem may exist as long as the CLC CONFIRM message is not received by the server. Whether a timer should be added after smc_close_final() needs to be discussed in the future. But even so, this patch provides a faster release for connection in above case, it should also be valuable. Fixes: 39f41f367b08 ("net/smc: common release code for non-accepted sockets") Signed-off-by: D. Wythe Acked-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/af_smc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'net/smc/af_smc.c') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 306d9e8cd1dd..81984c1c0e78 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -183,7 +183,7 @@ static int smc_release(struct socket *sock) { struct sock *sk = sock->sk; struct smc_sock *smc; - int rc = 0; + int old_state, rc = 0; if (!sk) goto out; @@ -191,8 +191,10 @@ static int smc_release(struct socket *sock) sock_hold(sk); /* sock_put below */ smc = smc_sk(sk); + old_state = sk->sk_state; + /* cleanup for a dangling non-blocking connect */ - if (smc->connect_nonblock && sk->sk_state == SMC_INIT) + if (smc->connect_nonblock && old_state == SMC_INIT) tcp_abort(smc->clcsock->sk, ECONNABORTED); if (cancel_work_sync(&smc->connect_work)) @@ -206,6 +208,10 @@ static int smc_release(struct socket *sock) else lock_sock(sk); + if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE && + !smc->use_fallback) + smc_close_active_abort(smc); + rc = __smc_release(smc); /* detach socket */ -- cgit v1.2.3 From 4d08b7b57ece83a1c31c633a7e4e27f121157f9c Mon Sep 17 00:00:00 2001 From: Tony Lu Date: Fri, 25 Feb 2022 14:56:57 +0800 Subject: net/smc: Fix cleanup when register ULP fails This patch calls smc_ib_unregister_client() when tcp_register_ulp() fails, and make sure to clean it up. Fixes: d7cd421da9da ("net/smc: Introduce TCP ULP support") Signed-off-by: Tony Lu Signed-off-by: David S. Miller --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/smc/af_smc.c') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 81984c1c0e78..284befa90967 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -3087,12 +3087,14 @@ static int __init smc_init(void) rc = tcp_register_ulp(&smc_ulp_ops); if (rc) { pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc); - goto out_sock; + goto out_ib; } static_branch_enable(&tcp_have_smc); return 0; +out_ib: + smc_ib_unregister_client(); out_sock: sock_unregister(PF_SMC); out_proto6: -- cgit v1.2.3