diff mbox series

[net,v1,1/3] net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT

Message ID 1698904324-33238-2-git-send-email-alibuda@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series bugfixs for smc | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1313 this patch: 1313
netdev/cc_maintainers warning 4 maintainers not CCed: tonylu@linux.alibaba.com pabeni@redhat.com edumazet@google.com guwen@linux.alibaba.com
netdev/build_clang success Errors and warnings before: 1341 this patch: 1341
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1341 this patch: 1341
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 41 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

D. Wythe Nov. 2, 2023, 5:52 a.m. UTC 
From: "D. Wythe" <alibuda@linux.alibaba.com>

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.

Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
---
 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(-)

Comments

Wenjia Zhang Nov. 2, 2023, 10:34 a.m. UTC | #1 
On 02.11.23 06:52, D. Wythe wrote:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
> 
> 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.
> 
> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
> Reviewed-by: Dust Li <dust.li@linux.alibaba.com>

Fixes tag?
D. Wythe Nov. 2, 2023, 1:28 p.m. UTC | #2 
On 11/2/23 6:34 PM, Wenjia Zhang wrote:
>
>
> On 02.11.23 06:52, D. Wythe wrote:
>> From: "D. Wythe" <alibuda@linux.alibaba.com>
>>
>> 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.
>>
>> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>> Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
>
> Fixes tag?

ops, i forget that.
diff mbox series

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index abd2667..da97f94 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 24745fd..e377980 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -377,4 +377,9 @@  void smc_fill_gid_list(struct smc_link_group *lgr,
 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 89105e9..01bdb79 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 dbdf03e..449ef45 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) {