This is a note to let you know that I've just added the patch titled
net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-smc-fix-dangling-sock-under-state-smc_appfinclos.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0224466a00bcdc9394d9ec0d233a282e43b21caf
Author: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx>
Date: Fri Nov 3 14:07:38 2023 +0800
net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT
[ Upstream commit 5211c9729484c923f8d2e06bd29f9322cc42bb8f ]
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 <alibuda@xxxxxxxxxxxxxxxxx>
Reviewed-by: Dust Li <dust.li@xxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index c0e4e587b4994..42d4211b6277e 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) {
@@ -1722,7 +1722,7 @@ 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 1f2b912c43d10..8358e96342e7b 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -374,4 +374,9 @@ 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 89105e95b4523..01bdb7909a14b 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 dbdf03e8aa5b5..449ef454b53be 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) {
