@@ -5197,6 +5197,9 @@ int hci_dev_close_sync(struct hci_dev *hdev)
*/
drain_workqueue(hdev->workqueue);
+ /* flush cmd work */
+ flush_work(&hdev->cmd_work);
+
hci_dev_lock(hdev);
hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
@@ -5234,8 +5237,6 @@ int hci_dev_close_sync(struct hci_dev *hdev)
clear_bit(HCI_INIT, &hdev->flags);
}
- /* flush cmd work */
- flush_work(&hdev->cmd_work);
/* Drop queues */
skb_queue_purge(&hdev->rx_q);
@@ -5519,9 +5519,17 @@ static void mgmt_remove_adv_monitor_complete(struct hci_dev *hdev,
{
struct mgmt_rp_remove_adv_monitor rp;
struct mgmt_pending_cmd *cmd = data;
- struct mgmt_cp_remove_adv_monitor *cp = cmd->param;
+ struct mgmt_cp_remove_adv_monitor *cp;
+
+ // if executing while device is closing down, status could
+ // be invalid as pending cmd could be removed by __mgmt_power_off
+ // so exit early if the device was busy.
+ if (status == -ECANCELED ||
+ cmd != pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev))
+ return;
hci_dev_lock(hdev);
+ cp = cmd->param;
rp.monitor_handle = cp->monitor_handle;
@@ -5540,6 +5548,10 @@ static void mgmt_remove_adv_monitor_complete(struct hci_dev *hdev,
static int mgmt_remove_adv_monitor_sync(struct hci_dev *hdev, void *data)
{
struct mgmt_pending_cmd *cmd = data;
+
+ if (cmd != pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev))
+ return -ECANCELED;
+
struct mgmt_cp_remove_adv_monitor *cp = cmd->param;
u16 handle = __le16_to_cpu(cp->monitor_handle);
@@ -9544,8 +9556,12 @@ void __mgmt_power_off(struct hci_dev *hdev)
*/
if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
match.mgmt_status = MGMT_STATUS_INVALID_INDEX;
- else
+ else {
+ match.mgmt_status = MGMT_STATUS_CANCELLED;
+ mgmt_pending_foreach(MGMT_OP_REMOVE_ADV_MONITOR, hdev,
+ cmd_status_rsp, &match);
match.mgmt_status = MGMT_STATUS_NOT_POWERED;
+ }
mgmt_pending_foreach(0, hdev, cmd_complete_rsp, &match);
When hci_dev is closing down, mgmt_power_off will free parts of the device. The freed memory can then be accessed when processing pending MGMT_OP_REMOVE_ADV_MONITOR cmds. Since submitting the command is allowed when it is powered off (as in previous discussions linked below), fix this by returning MGMT_STATUS_BUSY to pending MGMT_OP_REMOVE_ADV_MONITOR operations submitted as hci_dev_close_sync is running. Avoid processing pending cmds since doing so will lead to reacquiring the same lock. Add a sanity check within mgmt_remove_adv_monitor to ensure the cmd is still valid and exit early if not. BUG: KASAN: slab-use-after-free in mgmt_remove_adv_monitor_sync+0x3a/0xd0 net/bluetooth/mgmt.c:5543 Read of size 8 at addr ffff88814128f898 by task kworker/u9:4/5961 <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 mgmt_remove_adv_monitor_sync+0x3a/0xd0 net/bluetooth/mgmt.c:5543 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Freed by task 16022: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x196/0x420 mm/slub.c:4746 mgmt_pending_foreach+0xd1/0x130 net/bluetooth/mgmt_util.c:259 __mgmt_power_off+0x183/0x430 net/bluetooth/mgmt.c:9550 hci_dev_close_sync+0x6c4/0x11c0 net/bluetooth/hci_sync.c:5208 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline] hci_dev_close+0x112/0x210 net/bluetooth/hci_core.c:508 sock_do_ioctl+0x158/0x460 net/socket.c:1209 sock_ioctl+0x626/0x8e0 net/socket.c:1328 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Link: https://lore.kernel.org/lkml/20240424135903.24169-1-jlee@suse.com/ Reported-by: syzbot+479aff51bb361ef5aa18@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=479aff51bb361ef5aa18 Signed-off-by: Mazin Al Haddad <mazin@getstate.dev> --- Changes since v1: * Change return code to ECANCELED * Send out MGMT_STATUS_CANCELLED instead of MGMT_STATUS_BUSY * Style fixes net/bluetooth/hci_sync.c | 5 +++-- net/bluetooth/mgmt.c | 20 ++++++++++++++++++-- 2 files changed, 21 insertions(+), 4 deletions(-) base-commit: 499551201b5f4fd3c0618a3e95e3d0d15ea18f31