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Bluetooth: hci_core: Fix sleeping function called from invalid context
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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: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Tested-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
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@Vudentz
Vudentz committed Dec 12, 2024
1 parent 3e643e4 commit 4d94f05
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Showing 6 changed files with 97 additions and 57 deletions.
108 changes: 70 additions & 38 deletions include/net/bluetooth/hci_core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -2017,68 +2016,103 @@ 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,
__u8 encrypt);
__u8 encrypt);
void (*key_change_cfm) (struct hci_conn *conn, __u8 status);
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;

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->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);
}

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) {
Expand All @@ -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)
Expand Down
10 changes: 3 additions & 7 deletions net/bluetooth/hci_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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;
}
Expand All @@ -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;
}
Expand Down
6 changes: 6 additions & 0 deletions net/bluetooth/iso.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) {
Expand Down Expand Up @@ -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,
};
Expand Down
12 changes: 6 additions & 6 deletions net/bluetooth/l2cap_core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7217,16 +7217,18 @@ 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;
struct l2cap_conn *conn;
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) {
Expand Down Expand Up @@ -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));
Expand Down Expand Up @@ -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,
Expand Down
6 changes: 6 additions & 0 deletions net/bluetooth/rfcomm/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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
};

Expand Down
12 changes: 6 additions & 6 deletions net/bluetooth/sco.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1397,11 +1397,13 @@ int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
return lm;
}

static void sco_connect_cfm(struct hci_conn *hcon, __u8 status)
static bool sco_match(struct hci_conn *hcon)
{
if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
return;
return hcon->type == SCO_LINK || hcon->type == ESCO_LINK;
}

static void sco_connect_cfm(struct hci_conn *hcon, __u8 status)
{
BT_DBG("hcon %p bdaddr %pMR status %u", hcon, &hcon->dst, status);

if (!status) {
Expand All @@ -1416,9 +1418,6 @@ static void sco_connect_cfm(struct hci_conn *hcon, __u8 status)

static void sco_disconn_cfm(struct hci_conn *hcon, __u8 reason)
{
if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
return;

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

sco_conn_del(hcon, bt_to_errno(reason));
Expand All @@ -1444,6 +1443,7 @@ void sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb)

static struct hci_cb sco_cb = {
.name = "SCO",
.match = sco_match,
.connect_cfm = sco_connect_cfm,
.disconn_cfm = sco_disconn_cfm,
};
Expand Down

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