From 5211c9729484c923f8d2e06bd29f9322cc42bb8f Mon Sep 17 00:00:00 2001 From: "D. Wythe" Date: Fri, 3 Nov 2023 14:07:38 +0800 Subject: net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT Considering scenario: smc_cdc_rx_handler __smc_release sock_set_flag smc_close_active() sock_set_flag __set_bit(DEAD) __set_bit(DONE) Dues to __set_bit is not atomic, the DEAD or DONE might be lost. if the DEAD flag lost, the state SMC_CLOSED will be never be reached in smc_close_passive_work: if (sock_flag(sk, SOCK_DEAD) && smc_close_sent_any_close(conn)) { sk->sk_state = SMC_CLOSED; } else { /* just shutdown, but not yet closed locally */ sk->sk_state = SMC_APPFINCLOSEWAIT; } Replace sock_set_flags or __set_bit to set_bit will fix this problem. Since set_bit is atomic. Fixes: b38d732477e4 ("smc: socket closing and linkgroup cleanup") Signed-off-by: D. Wythe Reviewed-by: Dust Li Signed-off-by: David S. Miller --- net/smc/af_smc.c | 4 ++-- net/smc/smc.h | 5 +++++ net/smc/smc_cdc.c | 2 +- net/smc/smc_close.c | 2 +- 4 files changed, 9 insertions(+), 4 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index abd2667734d4..da97f946b79b 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -275,7 +275,7 @@ static int __smc_release(struct smc_sock *smc) if (!smc->use_fallback) { rc = smc_close_active(smc); - sock_set_flag(sk, SOCK_DEAD); + smc_sock_set_flag(sk, SOCK_DEAD); sk->sk_shutdown |= SHUTDOWN_MASK; } else { if (sk->sk_state != SMC_CLOSED) { @@ -1743,7 +1743,7 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc) if (new_clcsock) sock_release(new_clcsock); new_sk->sk_state = SMC_CLOSED; - sock_set_flag(new_sk, SOCK_DEAD); + smc_sock_set_flag(new_sk, SOCK_DEAD); sock_put(new_sk); /* final */ *new_smc = NULL; goto out; diff --git a/net/smc/smc.h b/net/smc/smc.h index 24745fde4ac2..e377980b8414 100644 --- a/net/smc/smc.h +++ b/net/smc/smc.h @@ -377,4 +377,9 @@ int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb); int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info); int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info); +static inline void smc_sock_set_flag(struct sock *sk, enum sock_flags flag) +{ + set_bit(flag, &sk->sk_flags); +} + #endif /* __SMC_H */ diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 89105e95b452..01bdb7909a14 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -385,7 +385,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, smc->sk.sk_shutdown |= RCV_SHUTDOWN; if (smc->clcsock && smc->clcsock->sk) smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN; - sock_set_flag(&smc->sk, SOCK_DONE); + smc_sock_set_flag(&smc->sk, SOCK_DONE); sock_hold(&smc->sk); /* sock_put in close_work */ if (!queue_work(smc_close_wq, &conn->close_work)) sock_put(&smc->sk); diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c index dbdf03e8aa5b..449ef454b53b 100644 --- a/net/smc/smc_close.c +++ b/net/smc/smc_close.c @@ -173,7 +173,7 @@ void smc_close_active_abort(struct smc_sock *smc) break; } - sock_set_flag(sk, SOCK_DEAD); + smc_sock_set_flag(sk, SOCK_DEAD); sk->sk_state_change(sk); if (release_clcsock) { -- cgit