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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: b38d732477 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
D. Wythe 2023-11-03 14:07:38 +08:00 committed by David S. Miller
parent d93f952857
commit 5211c97294
4 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
net/smc/af_smc.c
View File

@ -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;

5
net/smc/smc.h
View File

@ -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 */

2
net/smc/smc_cdc.c
View File

@ -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);

2
net/smc/smc_close.c
View File

@ -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) {