[PATCH v2 1/1] Bluetooth: serialize accept_q access

[PATCH v2 1/1] Bluetooth: serialize accept_q access

[Ren Wei]

From: Jiexun Wang <wangjiexun2025@gmail.com>

bt_sock_poll() walks the accept queue without synchronization, while
child teardown can unlink the same socket and drop its last reference.

Protect accept_q with a dedicated lock for queue updates and polling.
Also rework bt_accept_dequeue() to take temporary child references under
the queue lock before dropping it and locking the child socket.

Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Ren Wei <enjou1224z@gmail.com>
Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
---
Changes in v2:
- add Tested-by: Ren Wei <enjou1224z@gmail.com>
- resend to the public Bluetooth/netdev lists

 include/net/bluetooth/bluetooth.h |  1 +
 net/bluetooth/af_bluetooth.c      | 85 +++++++++++++++++++++++--------
 2 files changed, 66 insertions(+), 20 deletions(-)

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 69eed69f7f26..3faea66b1979 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -398,6 +398,7 @@ void baswap(bdaddr_t *dst, const bdaddr_t *src);
 struct bt_sock {
 	struct sock sk;
 	struct list_head accept_q;
+	spinlock_t accept_q_lock; /* protects accept_q */
 	struct sock *parent;
 	unsigned long flags;
 	void (*skb_msg_name)(struct sk_buff *, void *, int *);
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 2b94e2077203..f44e1ecc83d8 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock,
 
 	sock_init_data(sock, sk);
 	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
+	spin_lock_init(&bt_sk(sk)->accept_q_lock);
 
 	sock_reset_flag(sk, SOCK_ZAPPED);
 
@@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 {
 	const struct cred *old_cred;
 	struct pid *old_pid;
+	struct bt_sock *par = bt_sk(parent);
 
 	BT_DBG("parent %p, sk %p", parent, sk);
 
@@ -224,9 +226,12 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 	else
 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 
-	list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
 	bt_sk(sk)->parent = parent;
 
+	spin_lock_bh(&par->accept_q_lock);
+	list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q);
+	spin_unlock_bh(&par->accept_q_lock);
+
 	/* Copy credentials from parent since for incoming connections the
 	 * socket is allocated by the kernel.
 	 */
@@ -254,45 +259,73 @@ EXPORT_SYMBOL(bt_accept_enqueue);
  */
 void bt_accept_unlink(struct sock *sk)
 {
+	struct sock *parent = bt_sk(sk)->parent;
+
 	BT_DBG("sk %p state %d", sk, sk->sk_state);
 
+	spin_lock_bh(&bt_sk(parent)->accept_q_lock);
 	list_del_init(&bt_sk(sk)->accept_q);
-	sk_acceptq_removed(bt_sk(sk)->parent);
+	spin_unlock_bh(&bt_sk(parent)->accept_q_lock);
+
+	sk_acceptq_removed(parent);
 	bt_sk(sk)->parent = NULL;
 	sock_put(sk);
 }
 EXPORT_SYMBOL(bt_accept_unlink);
 
+static struct sock *bt_accept_get(struct sock *parent, struct sock *sk)
+{
+	struct bt_sock *bt = bt_sk(parent);
+	struct sock *next = NULL;
+
+	/* accept_q is modified from child teardown paths too, so take a
+	 * temporary reference before dropping the queue lock.
+	 */
+	spin_lock_bh(&bt->accept_q_lock);
+
+	if (sk) {
+		if (bt_sk(sk)->parent != parent)
+			goto out;
+
+		if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) {
+			next = &list_next_entry(bt_sk(sk), accept_q)->sk;
+			sock_hold(next);
+		}
+	} else if (!list_empty(&bt->accept_q)) {
+		next = &list_first_entry(&bt->accept_q,
+					 struct bt_sock, accept_q)->sk;
+		sock_hold(next);
+	}
+
+out:
+	spin_unlock_bh(&bt->accept_q_lock);
+	return next;
+}
+
 struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
 {
-	struct bt_sock *s, *n;
-	struct sock *sk;
+	struct sock *sk, *next;
 
 	BT_DBG("parent %p", parent);
 
 restart:
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
-		sk = (struct sock *)s;
-
+	for (sk = bt_accept_get(parent, NULL); sk; sk = next) {
 		/* Prevent early freeing of sk due to unlink and sock_kill */
-		sock_hold(sk);
 		lock_sock(sk);
 
 		/* Check sk has not already been unlinked via
 		 * bt_accept_unlink() due to serialisation caused by sk locking
 		 */
-		if (!bt_sk(sk)->parent) {
+		if (bt_sk(sk)->parent != parent) {
 			BT_DBG("sk %p, already unlinked", sk);
 			release_sock(sk);
 			sock_put(sk);
 
-			/* Restart the loop as sk is no longer in the list
-			 * and also avoid a potential infinite loop because
-			 * list_for_each_entry_safe() is not thread safe.
-			 */
 			goto restart;
 		}
 
+		next = bt_accept_get(parent, sk);
+
 		/* sk is safely in the parent list so reduce reference count */
 		sock_put(sk);
 
@@ -310,6 +343,8 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
 				sock_graft(sk, newsock);
 
 			release_sock(sk);
+			if (next)
+				sock_put(next);
 			return sk;
 		}
 
@@ -518,18 +553,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg);
 
 static inline __poll_t bt_accept_poll(struct sock *parent)
 {
-	struct bt_sock *s, *n;
+	struct bt_sock *bt = bt_sk(parent);
+	struct bt_sock *s;
 	struct sock *sk;
+	__poll_t mask = 0;
+
+	spin_lock_bh(&bt->accept_q_lock);
+	list_for_each_entry(s, &bt->accept_q, accept_q) {
+		int state;
 
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
 		sk = (struct sock *)s;
-		if (sk->sk_state == BT_CONNECTED ||
-		    (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
-		     sk->sk_state == BT_CONNECT2))
-			return EPOLLIN | EPOLLRDNORM;
+		state = READ_ONCE(sk->sk_state);
+
+		if (state == BT_CONNECTED ||
+		    (test_bit(BT_SK_DEFER_SETUP, &bt->flags) &&
+		     state == BT_CONNECT2)) {
+			mask = EPOLLIN | EPOLLRDNORM;
+			break;
+		}
 	}
+	spin_unlock_bh(&bt->accept_q_lock);
 
-	return 0;
+	return mask;
 }
 
 __poll_t bt_sock_poll(struct file *file, struct socket *sock,
-- 
2.34.1

RE: [v2,1/1] Bluetooth: serialize accept_q access

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2594 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1076861

---Test result---

Test Summary:
CheckPatch                    PENDING   0.31 seconds
GitLint                       PENDING   0.26 seconds
SubjectPrefix                 PASS      0.12 seconds
BuildKernel                   PASS      25.60 seconds
CheckAllWarning               PASS      28.35 seconds
CheckSparse                   PASS      27.45 seconds
BuildKernel32                 PASS      25.56 seconds
TestRunnerSetup               PASS      566.41 seconds
TestRunner_l2cap-tester       PASS      28.80 seconds
TestRunner_iso-tester         PASS      34.40 seconds
TestRunner_bnep-tester        PASS      6.45 seconds
TestRunner_mgmt-tester        FAIL      115.61 seconds
TestRunner_rfcomm-tester      PASS      10.75 seconds
TestRunner_sco-tester         FAIL      14.63 seconds
TestRunner_ioctl-tester       PASS      10.42 seconds
TestRunner_mesh-tester        FAIL      12.47 seconds
TestRunner_smp-tester         PASS      8.86 seconds
TestRunner_userchan-tester    PASS      6.87 seconds
IncrementalBuild              PENDING   0.51 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.111 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
BUG: sleeping function called from invalid context at net/core/sock.c:3782
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.703 seconds
Mesh - Send cancel - 2                               Timed out    1.994 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v2 1/1] Bluetooth: serialize accept_q access

[Paul Menzel]

Dear Ren,


Thank you for your patch.

Am 03.04.26 um 10:05 schrieb Ren Wei:
> From: Jiexun Wang <wangjiexun2025@gmail.com>
> 
> bt_sock_poll() walks the accept queue without synchronization, while
> child teardown can unlink the same socket and drop its last reference.
> 
> Protect accept_q with a dedicated lock for queue updates and polling.
> Also rework bt_accept_dequeue() to take temporary child references under
> the queue lock before dropping it and locking the child socket.
> 
> Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")
> Reported-by: Yifan Wu <yifanwucs@gmail.com>
> Reported-by: Juefei Pu <tomapufckgml@gmail.com>
> Co-developed-by: Yuan Tan <yuantan098@gmail.com>
> Signed-off-by: Yuan Tan <yuantan098@gmail.com>
> Suggested-by: Xin Liu <bird@lzu.edu.cn>
> Tested-by: Ren Wei <enjou1224z@gmail.com>
> Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
> ---
> Changes in v2:
> - add Tested-by: Ren Wei <enjou1224z@gmail.com>
> - resend to the public Bluetooth/netdev lists
> 
>   include/net/bluetooth/bluetooth.h |  1 +
>   net/bluetooth/af_bluetooth.c      | 85 +++++++++++++++++++++++--------
>   2 files changed, 66 insertions(+), 20 deletions(-)
> 
> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
> index 69eed69f7f26..3faea66b1979 100644
> --- a/include/net/bluetooth/bluetooth.h
> +++ b/include/net/bluetooth/bluetooth.h
> @@ -398,6 +398,7 @@ void baswap(bdaddr_t *dst, const bdaddr_t *src);
>   struct bt_sock {
>   	struct sock sk;
>   	struct list_head accept_q;
> +	spinlock_t accept_q_lock; /* protects accept_q */
>   	struct sock *parent;
>   	unsigned long flags;
>   	void (*skb_msg_name)(struct sk_buff *, void *, int *);
> diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
> index 2b94e2077203..f44e1ecc83d8 100644
> --- a/net/bluetooth/af_bluetooth.c
> +++ b/net/bluetooth/af_bluetooth.c
> @@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock,
>   
>   	sock_init_data(sock, sk);
>   	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
> +	spin_lock_init(&bt_sk(sk)->accept_q_lock);
>   
>   	sock_reset_flag(sk, SOCK_ZAPPED);
>   
> @@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
>   {
>   	const struct cred *old_cred;
>   	struct pid *old_pid;
> +	struct bt_sock *par = bt_sk(parent);
>   
>   	BT_DBG("parent %p, sk %p", parent, sk);
>   
> @@ -224,9 +226,12 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
>   	else
>   		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
>   
> -	list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
>   	bt_sk(sk)->parent = parent;
>   
> +	spin_lock_bh(&par->accept_q_lock);
> +	list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q);
> +	spin_unlock_bh(&par->accept_q_lock);
> +
>   	/* Copy credentials from parent since for incoming connections the
>   	 * socket is allocated by the kernel.
>   	 */
> @@ -254,45 +259,73 @@ EXPORT_SYMBOL(bt_accept_enqueue);
>    */
>   void bt_accept_unlink(struct sock *sk)
>   {
> +	struct sock *parent = bt_sk(sk)->parent;
> +
>   	BT_DBG("sk %p state %d", sk, sk->sk_state);
>   
> +	spin_lock_bh(&bt_sk(parent)->accept_q_lock);
>   	list_del_init(&bt_sk(sk)->accept_q);
> -	sk_acceptq_removed(bt_sk(sk)->parent);
> +	spin_unlock_bh(&bt_sk(parent)->accept_q_lock);
> +
> +	sk_acceptq_removed(parent);
>   	bt_sk(sk)->parent = NULL;
>   	sock_put(sk);
>   }
>   EXPORT_SYMBOL(bt_accept_unlink);
>   
> +static struct sock *bt_accept_get(struct sock *parent, struct sock *sk)
> +{
> +	struct bt_sock *bt = bt_sk(parent);
> +	struct sock *next = NULL;
> +
> +	/* accept_q is modified from child teardown paths too, so take a
> +	 * temporary reference before dropping the queue lock.
> +	 */
> +	spin_lock_bh(&bt->accept_q_lock);
> +
> +	if (sk) {
> +		if (bt_sk(sk)->parent != parent)
> +			goto out;
> +
> +		if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) {
> +			next = &list_next_entry(bt_sk(sk), accept_q)->sk;
> +			sock_hold(next);
> +		}
> +	} else if (!list_empty(&bt->accept_q)) {
> +		next = &list_first_entry(&bt->accept_q,
> +					 struct bt_sock, accept_q)->sk;
> +		sock_hold(next);
> +	}
> +
> +out:
> +	spin_unlock_bh(&bt->accept_q_lock);
> +	return next;
> +}
> +
>   struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
>   {
> -	struct bt_sock *s, *n;
> -	struct sock *sk;
> +	struct sock *sk, *next;
>   
>   	BT_DBG("parent %p", parent);
>   
>   restart:
> -	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
> -		sk = (struct sock *)s;
> -
> +	for (sk = bt_accept_get(parent, NULL); sk; sk = next) {
>   		/* Prevent early freeing of sk due to unlink and sock_kill */
> -		sock_hold(sk);
>   		lock_sock(sk);
>   
>   		/* Check sk has not already been unlinked via
>   		 * bt_accept_unlink() due to serialisation caused by sk locking
>   		 */
> -		if (!bt_sk(sk)->parent) {
> +		if (bt_sk(sk)->parent != parent) {
>   			BT_DBG("sk %p, already unlinked", sk);
>   			release_sock(sk);
>   			sock_put(sk);
>   
> -			/* Restart the loop as sk is no longer in the list
> -			 * and also avoid a potential infinite loop because
> -			 * list_for_each_entry_safe() is not thread safe.
> -			 */
>   			goto restart;
>   		}
>   
> +		next = bt_accept_get(parent, sk);
> +
>   		/* sk is safely in the parent list so reduce reference count */
>   		sock_put(sk);
>   
> @@ -310,6 +343,8 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
>   				sock_graft(sk, newsock);
>   
>   			release_sock(sk);
> +			if (next)
> +				sock_put(next);
>   			return sk;
>   		}
>   
> @@ -518,18 +553,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg);
>   
>   static inline __poll_t bt_accept_poll(struct sock *parent)
>   {
> -	struct bt_sock *s, *n;
> +	struct bt_sock *bt = bt_sk(parent);
> +	struct bt_sock *s;
>   	struct sock *sk;
> +	__poll_t mask = 0;
> +
> +	spin_lock_bh(&bt->accept_q_lock);
> +	list_for_each_entry(s, &bt->accept_q, accept_q) {
> +		int state;
>   
> -	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
>   		sk = (struct sock *)s;
> -		if (sk->sk_state == BT_CONNECTED ||
> -		    (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
> -		     sk->sk_state == BT_CONNECT2))
> -			return EPOLLIN | EPOLLRDNORM;
> +		state = READ_ONCE(sk->sk_state);
> +
> +		if (state == BT_CONNECTED ||
> +		    (test_bit(BT_SK_DEFER_SETUP, &bt->flags) &&
> +		     state == BT_CONNECT2)) {
> +			mask = EPOLLIN | EPOLLRDNORM;
> +			break;
> +		}
>   	}
> +	spin_unlock_bh(&bt->accept_q_lock);
>   
> -	return 0;
> +	return mask;
>   }
>   
>   __poll_t bt_sock_poll(struct file *file, struct socket *sock,

Google’s Gemini review service has a comment [1]. Do you think it’s 
valid and related?


Kind regards,

Paul


[1]: 
https://sashiko.dev/#/patchset/06a6b4549acba207847ce532dedbf1c95ab22d13.1774925231.git.wangjiexun2025%40gmail.com

Re: [PATCH v2 1/1] Bluetooth: serialize accept_q access

[Luiz Augusto von Dentz]

Hi Ren,

On Fri, Apr 3, 2026 at 4:05 AM Ren Wei <n05ec@lzu.edu.cn> wrote:
>
> From: Jiexun Wang <wangjiexun2025@gmail.com>
>
> bt_sock_poll() walks the accept queue without synchronization, while
> child teardown can unlink the same socket and drop its last reference.
>
> Protect accept_q with a dedicated lock for queue updates and polling.
> Also rework bt_accept_dequeue() to take temporary child references under
> the queue lock before dropping it and locking the child socket.
>
> Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")
> Reported-by: Yifan Wu <yifanwucs@gmail.com>
> Reported-by: Juefei Pu <tomapufckgml@gmail.com>
> Co-developed-by: Yuan Tan <yuantan098@gmail.com>
> Signed-off-by: Yuan Tan <yuantan098@gmail.com>
> Suggested-by: Xin Liu <bird@lzu.edu.cn>
> Tested-by: Ren Wei <enjou1224z@gmail.com>
> Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
> ---
> Changes in v2:
> - add Tested-by: Ren Wei <enjou1224z@gmail.com>
> - resend to the public Bluetooth/netdev lists
>
>  include/net/bluetooth/bluetooth.h |  1 +
>  net/bluetooth/af_bluetooth.c      | 85 +++++++++++++++++++++++--------
>  2 files changed, 66 insertions(+), 20 deletions(-)
>
> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
> index 69eed69f7f26..3faea66b1979 100644
> --- a/include/net/bluetooth/bluetooth.h
> +++ b/include/net/bluetooth/bluetooth.h
> @@ -398,6 +398,7 @@ void baswap(bdaddr_t *dst, const bdaddr_t *src);
>  struct bt_sock {
>         struct sock sk;
>         struct list_head accept_q;
> +       spinlock_t accept_q_lock; /* protects accept_q */
>         struct sock *parent;
>         unsigned long flags;
>         void (*skb_msg_name)(struct sk_buff *, void *, int *);
> diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
> index 2b94e2077203..f44e1ecc83d8 100644
> --- a/net/bluetooth/af_bluetooth.c
> +++ b/net/bluetooth/af_bluetooth.c
> @@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock,
>
>         sock_init_data(sock, sk);
>         INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
> +       spin_lock_init(&bt_sk(sk)->accept_q_lock);
>
>         sock_reset_flag(sk, SOCK_ZAPPED);
>
> @@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
>  {
>         const struct cred *old_cred;
>         struct pid *old_pid;
> +       struct bt_sock *par = bt_sk(parent);
>
>         BT_DBG("parent %p, sk %p", parent, sk);
>
> @@ -224,9 +226,12 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
>         else
>                 lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
>
> -       list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
>         bt_sk(sk)->parent = parent;
>
> +       spin_lock_bh(&par->accept_q_lock);
> +       list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q);
> +       spin_unlock_bh(&par->accept_q_lock);
> +
>         /* Copy credentials from parent since for incoming connections the
>          * socket is allocated by the kernel.
>          */
> @@ -254,45 +259,73 @@ EXPORT_SYMBOL(bt_accept_enqueue);
>   */
>  void bt_accept_unlink(struct sock *sk)
>  {
> +       struct sock *parent = bt_sk(sk)->parent;
> +
>         BT_DBG("sk %p state %d", sk, sk->sk_state);
>
> +       spin_lock_bh(&bt_sk(parent)->accept_q_lock);
>         list_del_init(&bt_sk(sk)->accept_q);
> -       sk_acceptq_removed(bt_sk(sk)->parent);
> +       spin_unlock_bh(&bt_sk(parent)->accept_q_lock);
> +
> +       sk_acceptq_removed(parent);
>         bt_sk(sk)->parent = NULL;
>         sock_put(sk);
>  }
>  EXPORT_SYMBOL(bt_accept_unlink);
>
> +static struct sock *bt_accept_get(struct sock *parent, struct sock *sk)
> +{
> +       struct bt_sock *bt = bt_sk(parent);
> +       struct sock *next = NULL;
> +
> +       /* accept_q is modified from child teardown paths too, so take a
> +        * temporary reference before dropping the queue lock.
> +        */
> +       spin_lock_bh(&bt->accept_q_lock);
> +
> +       if (sk) {
> +               if (bt_sk(sk)->parent != parent)
> +                       goto out;
> +
> +               if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) {
> +                       next = &list_next_entry(bt_sk(sk), accept_q)->sk;
> +                       sock_hold(next);
> +               }
> +       } else if (!list_empty(&bt->accept_q)) {
> +               next = &list_first_entry(&bt->accept_q,
> +                                        struct bt_sock, accept_q)->sk;
> +               sock_hold(next);
> +       }
> +
> +out:
> +       spin_unlock_bh(&bt->accept_q_lock);
> +       return next;
> +}
> +
>  struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
>  {
> -       struct bt_sock *s, *n;
> -       struct sock *sk;
> +       struct sock *sk, *next;
>
>         BT_DBG("parent %p", parent);
>
>  restart:
> -       list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
> -               sk = (struct sock *)s;
> -
> +       for (sk = bt_accept_get(parent, NULL); sk; sk = next) {
>                 /* Prevent early freeing of sk due to unlink and sock_kill */
> -               sock_hold(sk);
>                 lock_sock(sk);
>
>                 /* Check sk has not already been unlinked via
>                  * bt_accept_unlink() due to serialisation caused by sk locking
>                  */
> -               if (!bt_sk(sk)->parent) {
> +               if (bt_sk(sk)->parent != parent) {
>                         BT_DBG("sk %p, already unlinked", sk);
>                         release_sock(sk);
>                         sock_put(sk);
>
> -                       /* Restart the loop as sk is no longer in the list
> -                        * and also avoid a potential infinite loop because
> -                        * list_for_each_entry_safe() is not thread safe.
> -                        */
>                         goto restart;
>                 }
>
> +               next = bt_accept_get(parent, sk);
> +
>                 /* sk is safely in the parent list so reduce reference count */
>                 sock_put(sk);
>
> @@ -310,6 +343,8 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
>                                 sock_graft(sk, newsock);
>
>                         release_sock(sk);
> +                       if (next)
> +                               sock_put(next);
>                         return sk;
>                 }
>
> @@ -518,18 +553,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg);
>
>  static inline __poll_t bt_accept_poll(struct sock *parent)
>  {
> -       struct bt_sock *s, *n;
> +       struct bt_sock *bt = bt_sk(parent);
> +       struct bt_sock *s;
>         struct sock *sk;
> +       __poll_t mask = 0;
> +
> +       spin_lock_bh(&bt->accept_q_lock);
> +       list_for_each_entry(s, &bt->accept_q, accept_q) {
> +               int state;
>
> -       list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
>                 sk = (struct sock *)s;
> -               if (sk->sk_state == BT_CONNECTED ||
> -                   (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
> -                    sk->sk_state == BT_CONNECT2))
> -                       return EPOLLIN | EPOLLRDNORM;
> +               state = READ_ONCE(sk->sk_state);
> +
> +               if (state == BT_CONNECTED ||
> +                   (test_bit(BT_SK_DEFER_SETUP, &bt->flags) &&
> +                    state == BT_CONNECT2)) {
> +                       mask = EPOLLIN | EPOLLRDNORM;
> +                       break;
> +               }
>         }
> +       spin_unlock_bh(&bt->accept_q_lock);
>
> -       return 0;
> +       return mask;
>  }
>
>  __poll_t bt_sock_poll(struct file *file, struct socket *sock,
> --
> 2.34.1

https://sashiko.dev/#/patchset/06a6b4549acba207847ce532dedbf1c95ab22d13.1774925231.git.wangjiexun2025%40gmail.com

Seem valid to me.

-- 
Luiz Augusto von Dentz

[PATCH v3 1/1] Bluetooth: serialize accept_q access

[Ren Wei]

From: Jiexun Wang <wangjiexun2025@gmail.com>

bt_sock_poll() walks the accept queue without synchronization, while
child teardown can unlink the same socket and drop its last reference.

Protect accept_q with a dedicated lock for queue updates and polling.
Also rework bt_accept_dequeue() to take temporary child references under
the queue lock before dropping it and locking the child socket.

Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Ren Wei <enjou1224z@gmail.com>
Signed-off-by: Jiexun Wang <wangjiexun2025@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
---
Changes in v3:
- move sk_acceptq_added()/sk_acceptq_removed() inside accept_q_lock
  critical sections to serialize sk_ack_backlog updates with accept_q
  operations

Changes in v2:
- add Tested-by: Ren Wei <enjou1224z@gmail.com>
- resend to the public Bluetooth/netdev lists

 include/net/bluetooth/bluetooth.h |  1 +
 net/bluetooth/af_bluetooth.c      | 87 +++++++++++++++++++++++--------
 2 files changed, 66 insertions(+), 22 deletions(-)

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 69eed69f7f26..3faea66b1979 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -398,6 +398,7 @@ void baswap(bdaddr_t *dst, const bdaddr_t *src);
 struct bt_sock {
 	struct sock sk;
 	struct list_head accept_q;
+	spinlock_t accept_q_lock; /* protects accept_q */
 	struct sock *parent;
 	unsigned long flags;
 	void (*skb_msg_name)(struct sk_buff *, void *, int *);
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 2b94e2077203..fa14b9a915eb 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock,
 
 	sock_init_data(sock, sk);
 	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
+	spin_lock_init(&bt_sk(sk)->accept_q_lock);
 
 	sock_reset_flag(sk, SOCK_ZAPPED);
 
@@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 {
 	const struct cred *old_cred;
 	struct pid *old_pid;
+	struct bt_sock *par = bt_sk(parent);
 
 	BT_DBG("parent %p, sk %p", parent, sk);
 
@@ -224,9 +226,13 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 	else
 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 
-	list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
 	bt_sk(sk)->parent = parent;
 
+	spin_lock_bh(&par->accept_q_lock);
+	list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q);
+	sk_acceptq_added(parent);
+	spin_unlock_bh(&par->accept_q_lock);
+
 	/* Copy credentials from parent since for incoming connections the
 	 * socket is allocated by the kernel.
 	 */
@@ -244,8 +250,6 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 		bh_unlock_sock(sk);
 	else
 		release_sock(sk);
-
-	sk_acceptq_added(parent);
 }
 EXPORT_SYMBOL(bt_accept_enqueue);
 
@@ -254,45 +258,72 @@ EXPORT_SYMBOL(bt_accept_enqueue);
  */
 void bt_accept_unlink(struct sock *sk)
 {
+	struct sock *parent = bt_sk(sk)->parent;
+
 	BT_DBG("sk %p state %d", sk, sk->sk_state);
 
+	spin_lock_bh(&bt_sk(parent)->accept_q_lock);
 	list_del_init(&bt_sk(sk)->accept_q);
-	sk_acceptq_removed(bt_sk(sk)->parent);
+	sk_acceptq_removed(parent);
+	spin_unlock_bh(&bt_sk(parent)->accept_q_lock);
 	bt_sk(sk)->parent = NULL;
 	sock_put(sk);
 }
 EXPORT_SYMBOL(bt_accept_unlink);
 
+static struct sock *bt_accept_get(struct sock *parent, struct sock *sk)
+{
+	struct bt_sock *bt = bt_sk(parent);
+	struct sock *next = NULL;
+
+	/* accept_q is modified from child teardown paths too, so take a
+	 * temporary reference before dropping the queue lock.
+	 */
+	spin_lock_bh(&bt->accept_q_lock);
+
+	if (sk) {
+		if (bt_sk(sk)->parent != parent)
+			goto out;
+
+		if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) {
+			next = &list_next_entry(bt_sk(sk), accept_q)->sk;
+			sock_hold(next);
+		}
+	} else if (!list_empty(&bt->accept_q)) {
+		next = &list_first_entry(&bt->accept_q,
+					 struct bt_sock, accept_q)->sk;
+		sock_hold(next);
+	}
+
+out:
+	spin_unlock_bh(&bt->accept_q_lock);
+	return next;
+}
+
 struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
 {
-	struct bt_sock *s, *n;
-	struct sock *sk;
+	struct sock *sk, *next;
 
 	BT_DBG("parent %p", parent);
 
 restart:
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
-		sk = (struct sock *)s;
-
+	for (sk = bt_accept_get(parent, NULL); sk; sk = next) {
 		/* Prevent early freeing of sk due to unlink and sock_kill */
-		sock_hold(sk);
 		lock_sock(sk);
 
 		/* Check sk has not already been unlinked via
 		 * bt_accept_unlink() due to serialisation caused by sk locking
 		 */
-		if (!bt_sk(sk)->parent) {
+		if (bt_sk(sk)->parent != parent) {
 			BT_DBG("sk %p, already unlinked", sk);
 			release_sock(sk);
 			sock_put(sk);
 
-			/* Restart the loop as sk is no longer in the list
-			 * and also avoid a potential infinite loop because
-			 * list_for_each_entry_safe() is not thread safe.
-			 */
 			goto restart;
 		}
 
+		next = bt_accept_get(parent, sk);
+
 		/* sk is safely in the parent list so reduce reference count */
 		sock_put(sk);
 
@@ -310,6 +341,8 @@ struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
 				sock_graft(sk, newsock);
 
 			release_sock(sk);
+			if (next)
+				sock_put(next);
 			return sk;
 		}
 
@@ -518,18 +551,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg);
 
 static inline __poll_t bt_accept_poll(struct sock *parent)
 {
-	struct bt_sock *s, *n;
+	struct bt_sock *bt = bt_sk(parent);
+	struct bt_sock *s;
 	struct sock *sk;
+	__poll_t mask = 0;
+
+	spin_lock_bh(&bt->accept_q_lock);
+	list_for_each_entry(s, &bt->accept_q, accept_q) {
+		int state;
 
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
 		sk = (struct sock *)s;
-		if (sk->sk_state == BT_CONNECTED ||
-		    (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
-		     sk->sk_state == BT_CONNECT2))
-			return EPOLLIN | EPOLLRDNORM;
+		state = READ_ONCE(sk->sk_state);
+
+		if (state == BT_CONNECTED ||
+		    (test_bit(BT_SK_DEFER_SETUP, &bt->flags) &&
+		     state == BT_CONNECT2)) {
+			mask = EPOLLIN | EPOLLRDNORM;
+			break;
+		}
 	}
+	spin_unlock_bh(&bt->accept_q_lock);
 
-	return 0;
+	return mask;
 }
 
 __poll_t bt_sock_poll(struct file *file, struct socket *sock,
-- 
2.34.1

RE: [v3,1/1] Bluetooth: serialize accept_q access

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2593 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1077317

---Test result---

Test Summary:
CheckPatch                    PENDING   0.55 seconds
GitLint                       PENDING   0.25 seconds
SubjectPrefix                 PASS      0.07 seconds
BuildKernel                   PASS      26.64 seconds
CheckAllWarning               PASS      29.15 seconds
CheckSparse                   PASS      28.21 seconds
BuildKernel32                 PASS      26.20 seconds
TestRunnerSetup               PASS      587.43 seconds
TestRunner_l2cap-tester       PASS      28.27 seconds
TestRunner_iso-tester         PASS      35.73 seconds
TestRunner_bnep-tester        PASS      6.44 seconds
TestRunner_mgmt-tester        FAIL      116.41 seconds
TestRunner_rfcomm-tester      PASS      9.47 seconds
TestRunner_sco-tester         FAIL      14.60 seconds
TestRunner_ioctl-tester       PASS      10.24 seconds
TestRunner_mesh-tester        FAIL      12.53 seconds
TestRunner_smp-tester         PASS      8.56 seconds
TestRunner_userchan-tester    PASS      6.67 seconds
IncrementalBuild              PENDING   0.96 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.107 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
BUG: sleeping function called from invalid context at net/core/sock.c:3782
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.688 seconds
Mesh - Send cancel - 2                               Timed out    1.997 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

RE: [v3,1/1] Bluetooth: serialize accept_q access

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 6878 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1077317

---Test result---

Test Summary:
CheckPatch                    PENDING   0.54 seconds
GitLint                       PENDING   0.29 seconds
SubjectPrefix                 PASS      0.10 seconds
BuildKernel                   PASS      25.92 seconds
CheckAllWarning               PASS      28.56 seconds
CheckSparse                   PASS      27.26 seconds
BuildKernel32                 PASS      25.26 seconds
TestRunnerSetup               PASS      543.54 seconds
TestRunner_l2cap-tester       PASS      28.30 seconds
TestRunner_iso-tester         PASS      38.56 seconds
TestRunner_bnep-tester        PASS      6.48 seconds
TestRunner_mgmt-tester        FAIL      115.26 seconds
TestRunner_rfcomm-tester      PASS      9.59 seconds
TestRunner_sco-tester         FAIL      14.56 seconds
TestRunner_ioctl-tester       PASS      10.53 seconds
TestRunner_mesh-tester        FAIL      12.59 seconds
TestRunner_smp-tester         PASS      8.76 seconds
TestRunner_userchan-tester    PASS      12.94 seconds
TestRunner_6lowpan-tester     FAIL      8.65 seconds
IncrementalBuild              PENDING   0.31 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.109 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-g6ab4b2763829 #1 Not tainted
------------------------------------------------------
kworker/u5:2/117 is trying to acquire lock:
ffff888001946240 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x358/0x8d0

but task is already holding lock:
ffff88800215ac20 (&conn->lock){+.+.}-{3:3}, at: sco_connect_cfm+0x22d/0x8d0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&conn->lock){+.+.}-{3:3}:
       lock_acquire+0xf7/0x2c0
       _raw_spin_lock+0x2a/0x40
       sco_sock_connect+0x4d7/0x1280
       __sys_connect+0x1a3/0x260
       __x64_sys_connect+0x6e/0xb0
       do_syscall_64+0xa0/0x570
       entry_SYSCALL_64_after_hwframe+0x74/0x7c

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
       check_prev_add+0xe9/0xc70
       __lock_acquire+0x1457/0x1df0
       lock_acquire+0xf7/0x2c0
       lock_sock_nested+0x36/0xd0
       sco_connect_cfm+0x358/0x8d0
       hci_sync_conn_complete_evt+0x3d3/0x8e0
       hci_event_packet+0x74f/0xb10
       hci_rx_work+0x398/0xd00
       process_scheduled_works+0xb16/0x1ac0
       worker_thread+0x4ff/0xba0
       kthread+0x368/0x490
       ret_from_fork+0x498/0x7e0
       ret_from_fork_asm+0x19/0x30

other info that might help us debug this:

...
BUG: sleeping function called from invalid context at net/core/sock.c:3782
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 117, name: kworker/u5:2
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 117 Comm: kworker/u5:2 Not tainted 7.0.0-rc2-g6ab4b2763829 #1 PREEMPT(lazy) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x49/0x60
 __might_resched+0x2ea/0x500
 lock_sock_nested+0x47/0xd0
 ? sco_connect_cfm+0x358/0x8d0
 sco_connect_cfm+0x358/0x8d0
 ? hci_debugfs_create_conn+0x190/0x210
 ? __pfx_sco_connect_cfm+0x10/0x10
 hci_sync_conn_complete_evt+0x3d3/0x8e0
 hci_event_packet+0x74f/0xb10
 ? __pfx_hci_sync_conn_complete_evt+0x10/0x10
 ? __pfx_hci_event_packet+0x10/0x10
 ? mark_held_locks+0x49/0x80
 ? lockdep_hardirqs_on_prepare+0xd4/0x180
 ? _raw_spin_unlock_irqrestore+0x2c/0x50
 hci_rx_work+0x398/0xd00
 process_scheduled_works+0xb16/0x1ac0
 ? __pfx_process_scheduled_works+0x10/0x10
 ? lock_acquire+0xf7/0x2c0
 ? lock_is_held_type+0x9b/0x110
 ? __pfx_hci_rx_work+0x10/0x10
 worker_thread+0x4ff/0xba0
 ? _raw_spin_unlock_irqrestore+0x2c/0x50
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x368/0x490
 ? _raw_spin_unlock_irq+0x23/0x40
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x498/0x7e0
 ? __pfx_ret_from_fork+0x10/0x10
 ? __switch_to+0x9e4/0xe50
 ? __switch_to_asm+0x32/0x60
...
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.585 seconds
Mesh - Send cancel - 2                               Timed out    1.995 seconds
##############################
Test: TestRunner_6lowpan-tester - FAIL
Desc: Run 6lowpan-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-g6ab4b2763829 #1 Not tainted
------------------------------------------------------
kworker/0:1/12 is trying to acquire lock:
ffff8880026e0940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x75/0x180

but task is already holding lock:
ffffffffa084d720 (rtnl_mutex){+.+.}-{4:4}, at: lowpan_unregister_netdev+0xd/0x30

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (rtnl_mutex){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       lowpan_register_netdev+0x11/0x30
       chan_ready_cb+0x836/0xd00
       l2cap_recv_frame+0x6a06/0x8920
       l2cap_recv_acldata+0x790/0xdf0
       hci_rx_work+0x500/0xd00
       process_scheduled_works+0xb16/0x1ac0
       worker_thread+0x4ff/0xba0
       kthread+0x368/0x490
       ret_from_fork+0x498/0x7e0
       ret_from_fork_asm+0x19/0x30

-> #3 (&chan->lock#3/1){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       l2cap_chan_connect+0x74e/0x1980
       lowpan_control_write+0x523/0x660
       full_proxy_write+0x10b/0x190
       vfs_write+0x1c0/0xf60
       ksys_write+0xf1/0x1d0
       do_syscall_64+0xa0/0x570
       entry_SYSCALL_64_after_hwframe+0x74/0x7c

-> #2 (&conn->lock){+.+.}-{4:4}:
...
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



https://github.com/bluez/bluetooth-next/pull/45/checks

---
Regards,
Linux Bluetooth