Bluetooth: MGMT: Protect mgmt_pending list with its own lock

This uses a mutex to protect from concurrent access of mgmt_pending
list which can cause crashes like:

==================================================================
BUG: KASAN: slab-use-after-free in hci_sock_get_channel+0x60/0x68 net/bluetooth/hci_sock.c:91
Read of size 2 at addr ffff0000c48885b2 by task syz.4.334/7318

CPU: 0 UID: 0 PID: 7318 Comm: syz.4.334 Not tainted 6.15.0-rc7-syzkaller-g187899f4124a #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack+0x30/0x40 lib/dump_stack.c:94
dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
print_address_description+0xa8/0x254 mm/kasan/report.c:408
print_report+0x68/0x84 mm/kasan/report.c:521
kasan_report+0xb0/0x110 mm/kasan/report.c:634
__asan_report_load2_noabort+0x20/0x2c mm/kasan/report_generic.c:379
hci_sock_get_channel+0x60/0x68 net/bluetooth/hci_sock.c:91
mgmt_pending_find+0x7c/0x140 net/bluetooth/mgmt_util.c:223
pending_find net/bluetooth/mgmt.c:947 [inline]
remove_adv_monitor+0x44/0x1a4 net/bluetooth/mgmt.c:5445
hci_mgmt_cmd+0x780/0xc00 net/bluetooth/hci_sock.c:1712
hci_sock_sendmsg+0x544/0xbb0 net/bluetooth/hci_sock.c:1832
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
sock_write_iter+0x25c/0x378 net/socket.c:1131
new_sync_write fs/read_write.c:591 [inline]
vfs_write+0x62c/0x97c fs/read_write.c:684
ksys_write+0x120/0x210 fs/read_write.c:736
__do_sys_write fs/read_write.c:747 [inline]
__se_sys_write fs/read_write.c:744 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:744
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Allocated by task 7037:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:562
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4327 [inline]
__kmalloc_noprof+0x2fc/0x4c8 mm/slub.c:4339
kmalloc_noprof include/linux/slab.h:909 [inline]
sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2198
sk_alloc+0x44/0x3ac net/core/sock.c:2254
bt_sock_alloc+0x4c/0x300 net/bluetooth/af_bluetooth.c:148
hci_sock_create+0xa8/0x194 net/bluetooth/hci_sock.c:2202
bt_sock_create+0x14c/0x24c net/bluetooth/af_bluetooth.c:132
__sock_create+0x43c/0x91c net/socket.c:1541
sock_create net/socket.c:1599 [inline]
__sys_socket_create net/socket.c:1636 [inline]
__sys_socket+0xd4/0x1c0 net/socket.c:1683
__do_sys_socket net/socket.c:1697 [inline]
__se_sys_socket net/socket.c:1695 [inline]
__arm64_sys_socket+0x7c/0x94 net/socket.c:1695
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Freed by task 6607:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x68/0x88 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x17c/0x474 mm/slub.c:4841
sk_prot_free net/core/sock.c:2237 [inline]
__sk_destruct+0x4f4/0x760 net/core/sock.c:2332
sk_destruct net/core/sock.c:2360 [inline]
__sk_free+0x320/0x430 net/core/sock.c:2371
sk_free+0x60/0xc8 net/core/sock.c:2382
sock_put include/net/sock.h:1944 [inline]
mgmt_pending_free+0x88/0x118 net/bluetooth/mgmt_util.c:290
mgmt_pending_remove+0xec/0x104 net/bluetooth/mgmt_util.c:298
mgmt_set_powered_complete+0x418/0x5cc net/bluetooth/mgmt.c:1355
hci_cmd_sync_work+0x204/0x33c net/bluetooth/hci_sync.c:334
process_one_work+0x7e8/0x156c kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x958/0xed8 kernel/workqueue.c:3400
kthread+0x5fc/0x75c kernel/kthread.c:464
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

Fixes: a380b6cff1a2 ("Bluetooth: Add generic mgmt helper API")
Closes: https://syzkaller.appspot.com/bug?extid=0a7039d5d9986ff4ecec
Closes: https://syzkaller.appspot.com/bug?extid=cc0cc52e7f43dc9e6df1
Reported-by: [e-mail]
Tested-by: [e-mail]
Tested-by: [e-mail]
Signed-off-by: Dmitry Antipov <[e-mail]>
Signed-off-by: Luiz Augusto von Dentz <[e-mail]>

include/net/bluetooth/hci_core.h

···
 	struct hci_conn_hash	conn_hash;
 
 	struct list_head	mesh_pending;
+	struct mutex		mgmt_pending_lock;
 	struct list_head	mgmt_pending;
 	struct list_head	reject_list;
 	struct list_head	accept_list;

net/bluetooth/hci_core.c

···
 
 	mutex_init(&hdev->lock);
 	mutex_init(&hdev->req_lock);
+	mutex_init(&hdev->mgmt_pending_lock);
 
 	ida_init(&hdev->unset_handle_ida);
 

net/bluetooth/mgmt.c

···
 
 	send_settings_rsp(cmd->sk, cmd->opcode, match->hdev);
 
-	list_del(&cmd->list);
-
 	if (match->sk == NULL) {
 		match->sk = cmd->sk;
 		sock_hold(match->sk);
 	}
-
-	mgmt_pending_free(cmd);
 }
 
 static void cmd_status_rsp(struct mgmt_pending_cmd *cmd, void *data)
 {
 	u8 *status = data;
 
-	mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode, *status);
-	mgmt_pending_remove(cmd);
+	mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode, *status);
 }
 
 static void cmd_complete_rsp(struct mgmt_pending_cmd *cmd, void *data)
···
 
 	if (cmd->cmd_complete) {
 		cmd->cmd_complete(cmd, match->mgmt_status);
-		mgmt_pending_remove(cmd);
-
 		return;
 	}
 
···
 
 static int generic_cmd_complete(struct mgmt_pending_cmd *cmd, u8 status)
 {
-	return mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, status,
+	return mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, status,
 				 cmd->param, cmd->param_len);
 }
 
 static int addr_cmd_complete(struct mgmt_pending_cmd *cmd, u8 status)
 {
-	return mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, status,
+	return mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, status,
 				 cmd->param, sizeof(struct mgmt_addr_info));
 }
 
···
 
 	if (err) {
 		u8 mgmt_err = mgmt_status(err);
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode, mgmt_err);
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_err);
 		hci_dev_clear_flag(hdev, HCI_LIMITED_DISCOVERABLE);
 		goto done;
 	}
···
 
 	if (err) {
 		u8 mgmt_err = mgmt_status(err);
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode, mgmt_err);
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_err);
 		goto done;
 	}
 
···
 			new_settings(hdev, NULL);
 		}
 
-		mgmt_pending_foreach(MGMT_OP_SET_SSP, hdev, cmd_status_rsp,
-				     &mgmt_err);
+		mgmt_pending_foreach(MGMT_OP_SET_SSP, hdev, true,
+				     cmd_status_rsp, &mgmt_err);
 		return;
 	}
 
···
 		changed = hci_dev_test_and_clear_flag(hdev, HCI_SSP_ENABLED);
 	}
 
-	mgmt_pending_foreach(MGMT_OP_SET_SSP, hdev, settings_rsp, &match);
+	mgmt_pending_foreach(MGMT_OP_SET_SSP, hdev, true, settings_rsp, &match);
 
 	if (changed)
 		new_settings(hdev, match.sk);
···
 	bt_dev_dbg(hdev, "err %d", err);
 
 	if (status) {
-		mgmt_pending_foreach(MGMT_OP_SET_LE, hdev, cmd_status_rsp,
-							&status);
+		mgmt_pending_foreach(MGMT_OP_SET_LE, hdev, true, cmd_status_rsp,
+				     &status);
 		return;
 	}
 
-	mgmt_pending_foreach(MGMT_OP_SET_LE, hdev, settings_rsp, &match);
+	mgmt_pending_foreach(MGMT_OP_SET_LE, hdev, true, settings_rsp, &match);
 
 	new_settings(hdev, match.sk);
 
···
 	struct sock *sk = cmd->sk;
 
 	if (status) {
-		mgmt_pending_foreach(MGMT_OP_SET_MESH_RECEIVER, hdev,
+		mgmt_pending_foreach(MGMT_OP_SET_MESH_RECEIVER, hdev, true,
 				     cmd_status_rsp, &status);
 		return;
 	}
···
 
 	bt_dev_dbg(hdev, "err %d", err);
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 			  mgmt_status(err), hdev->dev_class, 3);
 
 	mgmt_pending_free(cmd);
···
 	bacpy(&rp.addr.bdaddr, &conn->dst);
 	rp.addr.type = link_to_bdaddr(conn->type, conn->dst_type);
 
-	err = mgmt_cmd_complete(cmd->sk, cmd->index, MGMT_OP_PAIR_DEVICE,
+	err = mgmt_cmd_complete(cmd->sk, cmd->hdev->id, MGMT_OP_PAIR_DEVICE,
 				status, &rp, sizeof(rp));
 
 	/* So we don't get further callbacks for this connection */
···
 		hci_update_passive_scan(hdev);
 	}
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 			  mgmt_status(status), &rp, sizeof(rp));
 	mgmt_pending_remove(cmd);
 
···
 		hci_update_passive_scan(hdev);
 	}
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 			  mgmt_status(status), &rp, sizeof(rp));
 	mgmt_pending_free(cmd);
 
···
 	    cmd != pending_find(MGMT_OP_START_SERVICE_DISCOVERY, hdev))
 		return;
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, mgmt_status(err),
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_status(err),
 			  cmd->param, 1);
 	mgmt_pending_remove(cmd);
 
···
 
 	bt_dev_dbg(hdev, "err %d", err);
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, mgmt_status(err),
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_status(err),
 			  cmd->param, 1);
 	mgmt_pending_remove(cmd);
 
···
 	u8 status = mgmt_status(err);
 
 	if (status) {
-		mgmt_pending_foreach(MGMT_OP_SET_ADVERTISING, hdev,
+		mgmt_pending_foreach(MGMT_OP_SET_ADVERTISING, hdev, true,
 				     cmd_status_rsp, &status);
 		return;
 	}
···
 	else
 		hci_dev_clear_flag(hdev, HCI_ADVERTISING);
 
-	mgmt_pending_foreach(MGMT_OP_SET_ADVERTISING, hdev, settings_rsp,
+	mgmt_pending_foreach(MGMT_OP_SET_ADVERTISING, hdev, true, settings_rsp,
 			     &match);
 
 	new_settings(hdev, match.sk);
···
 		 */
 		hci_dev_clear_flag(hdev, HCI_BREDR_ENABLED);
 
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode, mgmt_err);
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_err);
 	} else {
 		send_settings_rsp(cmd->sk, MGMT_OP_SET_BREDR, hdev);
 		new_settings(hdev, cmd->sk);
···
 	if (err) {
 		u8 mgmt_err = mgmt_status(err);
 
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode, mgmt_err);
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode, mgmt_err);
 		goto done;
 	}
 
···
 		rp.max_tx_power = HCI_TX_POWER_INVALID;
 	}
 
-	mgmt_cmd_complete(cmd->sk, cmd->index, MGMT_OP_GET_CONN_INFO, status,
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, MGMT_OP_GET_CONN_INFO, status,
 			  &rp, sizeof(rp));
 
 	mgmt_pending_free(cmd);
···
 	}
 
 complete:
-	mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, status, &rp,
+	mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode, status, &rp,
 			  sizeof(rp));
 
 	mgmt_pending_free(cmd);
···
 	rp.instance = cp->instance;
 
 	if (err)
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode,
 				mgmt_status(err));
 	else
-		mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 				  mgmt_status(err), &rp, sizeof(rp));
 
 	add_adv_complete(hdev, cmd->sk, cp->instance, err);
···
 
 		hci_remove_adv_instance(hdev, cp->instance);
 
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode,
 				mgmt_status(err));
 	} else {
-		mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 				  mgmt_status(err), &rp, sizeof(rp));
 	}
 
···
 	rp.instance = cp->instance;
 
 	if (err)
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode,
 				mgmt_status(err));
 	else
-		mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 				  mgmt_status(err), &rp, sizeof(rp));
 
 	mgmt_pending_free(cmd);
···
 	rp.instance = cp->instance;
 
 	if (err)
-		mgmt_cmd_status(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_status(cmd->sk, cmd->hdev->id, cmd->opcode,
 				mgmt_status(err));
 	else
-		mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+		mgmt_cmd_complete(cmd->sk, cmd->hdev->id, cmd->opcode,
 				  MGMT_STATUS_SUCCESS, &rp, sizeof(rp));
 
 	mgmt_pending_free(cmd);
···
 	if (test_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks))
 		return;
 
-	mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &match);
+	mgmt_pending_foreach(0, hdev, true, cmd_complete_rsp, &match);
 
 	if (hci_dev_test_flag(hdev, HCI_UNCONFIGURED)) {
 		mgmt_index_event(MGMT_EV_UNCONF_INDEX_REMOVED, hdev, NULL, 0,
···
 		hci_update_passive_scan(hdev);
 	}
 
-	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, settings_rsp, &match);
+	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, true, settings_rsp,
+			     &match);
 
 	new_settings(hdev, match.sk);
 
···
 	struct cmd_lookup match = { NULL, hdev };
 	u8 zero_cod[] = { 0, 0, 0 };
 
-	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, settings_rsp, &match);
+	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, true, settings_rsp,
+			     &match);
 
 	/* If the power off is because of hdev unregistration let
 	 * use the appropriate INVALID_INDEX status. Otherwise use
···
 	else
 		match.mgmt_status = MGMT_STATUS_NOT_POWERED;
 
-	mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &match);
+	mgmt_pending_foreach(0, hdev, true, cmd_complete_rsp, &match);
 
 	if (memcmp(hdev->dev_class, zero_cod, sizeof(zero_cod)) != 0) {
 		mgmt_limited_event(MGMT_EV_CLASS_OF_DEV_CHANGED, hdev,
···
 	device_unpaired(hdev, &cp->addr.bdaddr, cp->addr.type, cmd->sk);
 
 	cmd->cmd_complete(cmd, 0);
-	mgmt_pending_remove(cmd);
 }
 
 bool mgmt_powering_down(struct hci_dev *hdev)
···
 	struct mgmt_cp_disconnect *cp;
 	struct mgmt_pending_cmd *cmd;
 
-	mgmt_pending_foreach(MGMT_OP_UNPAIR_DEVICE, hdev, unpair_device_rsp,
-			     hdev);
+	mgmt_pending_foreach(MGMT_OP_UNPAIR_DEVICE, hdev, true,
+			     unpair_device_rsp, hdev);
 
 	cmd = pending_find(MGMT_OP_DISCONNECT, hdev);
 	if (!cmd)
···
 
 	if (status) {
 		u8 mgmt_err = mgmt_status(status);
-		mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev,
+		mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev, true,
 				     cmd_status_rsp, &mgmt_err);
 		return;
 	}
···
 	else
 		changed = hci_dev_test_and_clear_flag(hdev, HCI_LINK_SECURITY);
 
-	mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev, settings_rsp,
-			     &match);
+	mgmt_pending_foreach(MGMT_OP_SET_LINK_SECURITY, hdev, true,
+			     settings_rsp, &match);
 
 	if (changed)
 		new_settings(hdev, match.sk);
···
 {
 	struct cmd_lookup match = { NULL, hdev, mgmt_status(status) };
 
-	mgmt_pending_foreach(MGMT_OP_SET_DEV_CLASS, hdev, sk_lookup, &match);
-	mgmt_pending_foreach(MGMT_OP_ADD_UUID, hdev, sk_lookup, &match);
-	mgmt_pending_foreach(MGMT_OP_REMOVE_UUID, hdev, sk_lookup, &match);
+	mgmt_pending_foreach(MGMT_OP_SET_DEV_CLASS, hdev, false, sk_lookup,
+			     &match);
+	mgmt_pending_foreach(MGMT_OP_ADD_UUID, hdev, false, sk_lookup,
+			     &match);
+	mgmt_pending_foreach(MGMT_OP_REMOVE_UUID, hdev, false, sk_lookup,
+			     &match);
 
 	if (!status) {
 		mgmt_limited_event(MGMT_EV_CLASS_OF_DEV_CHANGED, hdev, dev_class,

net/bluetooth/mgmt_util.c

···
 struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
 					   struct hci_dev *hdev)
 {
-	struct mgmt_pending_cmd *cmd;
+	struct mgmt_pending_cmd *cmd, *tmp;
 
-	list_for_each_entry(cmd, &hdev->mgmt_pending, list) {
+	mutex_lock(&hdev->mgmt_pending_lock);
+
+	list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
 		if (hci_sock_get_channel(cmd->sk) != channel)
 			continue;
-		if (cmd->opcode == opcode)
+
+		if (cmd->opcode == opcode) {
+			mutex_unlock(&hdev->mgmt_pending_lock);
 			return cmd;
+		}
 	}
+
+	mutex_unlock(&hdev->mgmt_pending_lock);
 
 	return NULL;
 }
 
-void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev,
+void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
 			  void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
 			  void *data)
 {
 	struct mgmt_pending_cmd *cmd, *tmp;
 
+	mutex_lock(&hdev->mgmt_pending_lock);
+
 	list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
 		if (opcode > 0 && cmd->opcode != opcode)
 			continue;
 
+		if (remove)
+			list_del(&cmd->list);
+
 		cb(cmd, data);
+
+		if (remove)
+			mgmt_pending_free(cmd);
 	}
+
+	mutex_unlock(&hdev->mgmt_pending_lock);
 }
 
 struct mgmt_pending_cmd *mgmt_pending_new(struct sock *sk, u16 opcode,
···
 		return NULL;
 
 	cmd->opcode = opcode;
-	cmd->index = hdev->id;
+	cmd->hdev = hdev;
 
 	cmd->param = kmemdup(data, len, GFP_KERNEL);
 	if (!cmd->param) {
···
 	if (!cmd)
 		return NULL;
 
+	mutex_lock(&hdev->mgmt_pending_lock);
 	list_add_tail(&cmd->list, &hdev->mgmt_pending);
+	mutex_unlock(&hdev->mgmt_pending_lock);
 
 	return cmd;
 }
···
 
 void mgmt_pending_remove(struct mgmt_pending_cmd *cmd)
 {
+	mutex_lock(&cmd->hdev->mgmt_pending_lock);
 	list_del(&cmd->list);
+	mutex_unlock(&cmd->hdev->mgmt_pending_lock);
+
 	mgmt_pending_free(cmd);
 }
 

net/bluetooth/mgmt_util.h

···
 struct mgmt_pending_cmd {
 	struct list_head list;
 	u16 opcode;
-	int index;
+	struct hci_dev *hdev;
 	void *param;
 	size_t param_len;
 	struct sock *sk;
···
 
 struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
 					   struct hci_dev *hdev);
-void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev,
+void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
 			  void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
 			  void *data);
 struct mgmt_pending_cmd *mgmt_pending_add(struct sock *sk, u16 opcode,