Commit 4d94f055 authored by Luiz Augusto von Dentz's avatar Luiz Augusto von Dentz
Browse files

Bluetooth: hci_core: Fix sleeping function called from invalid context 



This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: default avatar <syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com>
Tested-by: default avatar <syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614


Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
parent 3e643e4e

include/net/bluetooth/hci_core.h

+70 −38
Original line number Diff line number Diff line
@@ -804,7 +804,6 @@ struct hci_conn_params { 
extern struct list_head hci_dev_list;

extern struct list_head hci_cb_list;

extern rwlock_t hci_dev_list_lock;

extern struct mutex hci_cb_list_lock;



#define hci_dev_set_flag(hdev, nr)             set_bit((nr), (hdev)->dev_flags)

#define hci_dev_clear_flag(hdev, nr)           clear_bit((nr), (hdev)->dev_flags)
@@ -2017,6 +2016,7 @@ struct hci_cb { 


	char *name;



	bool (*match)		(struct hci_conn *conn);

	void (*connect_cfm)	(struct hci_conn *conn, __u8 status);

	void (*disconn_cfm)	(struct hci_conn *conn, __u8 status);

	void (*security_cfm)	(struct hci_conn *conn, __u8 status,
@@ -2025,16 +2025,38 @@ struct hci_cb { 
	void (*role_switch_cfm)	(struct hci_conn *conn, __u8 status, __u8 role);

};



static inline void hci_cb_lookup(struct hci_conn *conn, struct list_head *list)

{

	struct hci_cb *cb, *cpy;



	rcu_read_lock();

	list_for_each_entry_rcu(cb, &hci_cb_list, list) {

		if (cb->match && cb->match(conn)) {

			cpy = kmalloc(sizeof(*cpy), GFP_ATOMIC);

			if (!cpy)

				break;



			*cpy = *cb;

			INIT_LIST_HEAD(&cpy->list);

			list_add_rcu(&cpy->list, list);

		}

	}

	rcu_read_unlock();

}



static inline void hci_connect_cfm(struct hci_conn *conn, __u8 status)

{

	struct hci_cb *cb;

	struct list_head list;

	struct hci_cb *cb, *tmp;



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

	INIT_LIST_HEAD(&list);

	hci_cb_lookup(conn, &list);



	list_for_each_entry_safe(cb, tmp, &list, list) {

		if (cb->connect_cfm)

			cb->connect_cfm(conn, status);

		kfree(cb);

	}

	mutex_unlock(&hci_cb_list_lock);



	if (conn->connect_cfm_cb)

		conn->connect_cfm_cb(conn, status);
@@ -2042,43 +2064,55 @@ static inline void hci_connect_cfm(struct hci_conn *conn, __u8 status) 


static inline void hci_disconn_cfm(struct hci_conn *conn, __u8 reason)

{

	struct hci_cb *cb;

	struct list_head list;

	struct hci_cb *cb, *tmp;



	INIT_LIST_HEAD(&list);

	hci_cb_lookup(conn, &list);



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

	list_for_each_entry_safe(cb, tmp, &list, list) {

		if (cb->disconn_cfm)

			cb->disconn_cfm(conn, reason);

		kfree(cb);

	}

	mutex_unlock(&hci_cb_list_lock);



	if (conn->disconn_cfm_cb)

		conn->disconn_cfm_cb(conn, reason);

}



static inline void hci_auth_cfm(struct hci_conn *conn, __u8 status)

static inline void hci_security_cfm(struct hci_conn *conn, __u8 status,

				    __u8 encrypt)

{

	struct hci_cb *cb;

	__u8 encrypt;



	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))

		return;

	struct list_head list;

	struct hci_cb *cb, *tmp;



	encrypt = test_bit(HCI_CONN_ENCRYPT, &conn->flags) ? 0x01 : 0x00;

	INIT_LIST_HEAD(&list);

	hci_cb_lookup(conn, &list);



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

	list_for_each_entry_safe(cb, tmp, &list, list) {

		if (cb->security_cfm)

			cb->security_cfm(conn, status, encrypt);

		kfree(cb);

	}

	mutex_unlock(&hci_cb_list_lock);



	if (conn->security_cfm_cb)

		conn->security_cfm_cb(conn, status);

}



static inline void hci_auth_cfm(struct hci_conn *conn, __u8 status)

{

	__u8 encrypt;



	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))

		return;



	encrypt = test_bit(HCI_CONN_ENCRYPT, &conn->flags) ? 0x01 : 0x00;



	hci_security_cfm(conn, status, encrypt);

}



static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status)

{

	struct hci_cb *cb;

	__u8 encrypt;



	if (conn->state == BT_CONFIG) {
@@ -2105,40 +2139,38 @@ static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status) 
			conn->sec_level = conn->pending_sec_level;

	}



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

		if (cb->security_cfm)

			cb->security_cfm(conn, status, encrypt);

	}

	mutex_unlock(&hci_cb_list_lock);



	if (conn->security_cfm_cb)

		conn->security_cfm_cb(conn, status);

	hci_security_cfm(conn, status, encrypt);

}



static inline void hci_key_change_cfm(struct hci_conn *conn, __u8 status)

{

	struct hci_cb *cb;

	struct list_head list;

	struct hci_cb *cb, *tmp;



	INIT_LIST_HEAD(&list);

	hci_cb_lookup(conn, &list);



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

	list_for_each_entry_safe(cb, tmp, &list, list) {

		if (cb->key_change_cfm)

			cb->key_change_cfm(conn, status);

		kfree(cb);

	}

	mutex_unlock(&hci_cb_list_lock);

}



static inline void hci_role_switch_cfm(struct hci_conn *conn, __u8 status,

								__u8 role)

{

	struct hci_cb *cb;

	struct list_head list;

	struct hci_cb *cb, *tmp;



	INIT_LIST_HEAD(&list);

	hci_cb_lookup(conn, &list);



	mutex_lock(&hci_cb_list_lock);

	list_for_each_entry(cb, &hci_cb_list, list) {

	list_for_each_entry_safe(cb, tmp, &list, list) {

		if (cb->role_switch_cfm)

			cb->role_switch_cfm(conn, status, role);

		kfree(cb);

	}

	mutex_unlock(&hci_cb_list_lock);

}



static inline bool hci_bdaddr_is_rpa(bdaddr_t *bdaddr, u8 addr_type)

net/bluetooth/hci_core.c

+3 −7
Original line number Diff line number Diff line
@@ -57,7 +57,6 @@ DEFINE_RWLOCK(hci_dev_list_lock); 


/* HCI callback list */

LIST_HEAD(hci_cb_list);

DEFINE_MUTEX(hci_cb_list_lock);



/* HCI ID Numbering */

static DEFINE_IDA(hci_index_ida);
@@ -2993,9 +2992,7 @@ int hci_register_cb(struct hci_cb *cb) 
{

	BT_DBG("%p name %s", cb, cb->name);



	mutex_lock(&hci_cb_list_lock);

	list_add_tail(&cb->list, &hci_cb_list);

	mutex_unlock(&hci_cb_list_lock);

	list_add_tail_rcu(&cb->list, &hci_cb_list);



	return 0;

}
@@ -3005,9 +3002,8 @@ int hci_unregister_cb(struct hci_cb *cb) 
{

	BT_DBG("%p name %s", cb, cb->name);



	mutex_lock(&hci_cb_list_lock);

	list_del(&cb->list);

	mutex_unlock(&hci_cb_list_lock);

	list_del_rcu(&cb->list);

	synchronize_rcu();



	return 0;

}

net/bluetooth/iso.c

+6 −0
Original line number Diff line number Diff line
@@ -2118,6 +2118,11 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags) 
	return HCI_LM_ACCEPT;

}



static bool iso_match(struct hci_conn *hcon)

{

	return hcon->type == ISO_LINK || hcon->type == LE_LINK;

}



static void iso_connect_cfm(struct hci_conn *hcon, __u8 status)

{

	if (hcon->type != ISO_LINK) {
@@ -2299,6 +2304,7 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 


static struct hci_cb iso_cb = {

	.name		= "ISO",

	.match		= iso_match,

	.connect_cfm	= iso_connect_cfm,

	.disconn_cfm	= iso_disconn_cfm,

};

net/bluetooth/l2cap_core.c

+6 −6
Original line number Diff line number Diff line
@@ -7217,6 +7217,11 @@ static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c, 
	return NULL;

}



static bool l2cap_match(struct hci_conn *hcon)

{

	return hcon->type == ACL_LINK || hcon->type == LE_LINK;

}



static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)

{

	struct hci_dev *hdev = hcon->hdev;
@@ -7224,9 +7229,6 @@ static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status) 
	struct l2cap_chan *pchan;

	u8 dst_type;



	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)

		return;



	BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);



	if (status) {
@@ -7291,9 +7293,6 @@ int l2cap_disconn_ind(struct hci_conn *hcon) 


static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)

{

	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)

		return;



	BT_DBG("hcon %p reason %d", hcon, reason);



	l2cap_conn_del(hcon, bt_to_errno(reason));
@@ -7572,6 +7571,7 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) 


static struct hci_cb l2cap_cb = {

	.name		= "L2CAP",

	.match		= l2cap_match,

	.connect_cfm	= l2cap_connect_cfm,

	.disconn_cfm	= l2cap_disconn_cfm,

	.security_cfm	= l2cap_security_cfm,

net/bluetooth/rfcomm/core.c

+6 −0
Original line number Diff line number Diff line
@@ -2134,6 +2134,11 @@ static int rfcomm_run(void *unused) 
	return 0;

}



static bool rfcomm_match(struct hci_conn *hcon)

{

	return hcon->type == ACL_LINK;

}



static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)

{

	struct rfcomm_session *s;
@@ -2180,6 +2185,7 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt) 


static struct hci_cb rfcomm_cb = {

	.name		= "RFCOMM",

	.match		= rfcomm_match,

	.security_cfm	= rfcomm_security_cfm

};