From: zhangchen zhangchen01@kylinos.cn

If hci_resume_dev before hci_unregister_dev, the hci command will timeout and the reference count of hdev will not reset to zero. Then the node "hci0" will not release.

The output in question is as follows: [ 3391.553518][ 7] [T247244] Bluetooth: hci0: command 0x0c01 tx timeout [ 3391.553588][ 7] [T264732] Bluetooth: hci0: Opcode 0x0c01 failed: -110 [ 3393.569514][ 3] [T247244] Bluetooth: hci0: command 0x0c01 tx timeout [ 3393.569515][ 3] [T264732] Bluetooth: hci0: Opcode 0x0c1a failed: -110 [ 3393.709645][ 6] [T104579] usb 10-1: new full-speed USB device number 95 using xhci-hcd [ 3393.862194][ 6] [T104579] usb 10-1: New USB device found, idVendor=13d3, idProduct=3570, bcdDevice= 0.00 [ 3393.862205][ 6] [T104579] usb 10-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 3393.862208][ 6] [T104579] usb 10-1: Product: Bluetooth Radio [ 3393.862210][ 6] [T104579] usb 10-1: Manufacturer: Realtek [ 3393.862212][ 6] [T104579] usb 10-1: SerialNumber: 00e04c000001 [ 3393.867589][ 6] [T247244] Bluetooth: hci1: RTL: examining hci_ver=0b hci_rev=000b lmp_ver=0b lmp_subver=8852 [ 3393.868573][ 6] [T247244] Bluetooth: hci1: RTL: rom_version status=0 version=1 [ 3393.868583][ 6] [T247244] Bluetooth: hci1: RTL: loading rtl_bt/rtl8852bu_fw.bin [ 3393.868672][ 6] [T247244] Bluetooth: hci1: RTL: loading rtl_bt/rtl8852bu_config.bin [ 3393.869699][ 6] [T247244] Bluetooth: hci1: RTL: cfg_sz 6, total sz 65603

The call sequence in question is as follows: usb disconnect: btusb_disconnect hci_unregister_dev hci_dev_set_flag hci_cmd_sync_clear hci_unregister_suspend_notifier hci_dev_do_close device_del

device resume: hci_suspend_notifier hci_resume_dev hci_resume_sync hci_set_event_mask_sync __hci_cmd_sync_status __hci_cmd_sync_status_sk __hci_cmd_sync_sk wait_event_interruptible_timeout

The output after adding debug information in question is as follows: [ 6378.366215][ 6] [T434033] hci_resume_dev hci name hci0 [ 6378.366218][ 6] [T434033] hci_resume_sync set event mask sync [ 6378.366219][ 6] [T434033] hci_set_event_mask_sync [ 6378.366220][ 6] [T434033] __hci_cmd_sync_sk hci name hci0 Opcode 0x0c01 [ 6378.366227][ 6] [T434033] __hci_cmd_sync_sk wait event interruptible timeout [ 6378.367632][ 6] [T420012] btusb_disconnect intf 0000000024117fc1 [ 6378.367637][ 6] [T420012] btusb_disconnect hci_unregister_dev [ 6378.367638][ 6] [T420012] hci_unregister_dev 0000000064bfd783 name hci0 bus 1 [ 6378.367641][ 6] [T420012] hci_unregister_dev set flag [ 6378.367804][ 6] [T420012] hci_unregister_dev cmd sync clear [ 6378.367807][ 6] [T420012] hci_unregister_dev unregister suspend notifier [ 6380.367544][ 6] [T434033] __hci_cmd_sync_sk cmd timeout [ 6380.367542][ 6] [T197498] Bluetooth: hci0: command 0x0c01 tx timeout [ 6380.367550][ 6] [T434033] __hci_cmd_sync_sk hci0 end: err -110 [ 6380.367552][ 6] [T434033] Bluetooth: hci0: Opcode 0x0c01 failed: -110 [ 6380.367555][ 6] [T434033] hci_resume_sync clear event filter [ 6380.367556][ 6] [T434033] hci_resume_sync resume scan sync [ 6380.367558][ 6] [T434033] __hci_cmd_sync_sk hci name hci0 Opcode 0x0c1a [ 6380.367561][ 6] [T434033] __hci_cmd_sync_sk wait event interruptible timeout [ 6382.383538][ 6] [T197498] Bluetooth: hci0: command 0x0c01 tx timeout [ 6382.383593][ 6] [T434033] __hci_cmd_sync_sk hci0 end: err -110 [ 6382.383597][ 6] [T434033] Bluetooth: hci0: Opcode 0x0c1a failed: -110

The output after adding debug information in normal is as follows: [50.039156][ 6] [ T8360] btusb_disconnect intf 00000000fca35842 [50.039160][ 6] [ T8360] btusb_disconnect hci_unregister_dev [50.039162][ 6] [ T8360] hci_unregister_dev 000000002422b946 name hci0 bus 1 [50.039164][ 6] [ T8360] hci_unregister_dev set flag [50.039224][ 6] [ T8360] hci_unregister_dev cmd sync clear [50.039227][ 5] [ T8360] hci_unregister_dev unregister suspend notifier [50.043542][ 5] [ T8284] hci_resume_dev hci name hci0

This patch add hci_cancel_cmd_sync in hci_unregister_dev to wake up hdev->req_wait_q, and stop __hci_cmd_sync_sk by judging the HCI_UNREGISTER flag. Then stopping hci_resume_dev process based on the returned error code.

Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier") Cc: stable@vger.kernel.org Signed-off-by: zhangchen zhangchen01@kylinos.cn --- net/bluetooth/hci_core.c | 6 ++++++ net/bluetooth/hci_sync.c | 22 ++++++++++++++++------ 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 3418d7b964a1..c977bcba3e76 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -50,6 +50,7 @@ static void hci_rx_work(struct work_struct *work); static void hci_cmd_work(struct work_struct *work); static void hci_tx_work(struct work_struct *work); +static void hci_cancel_cmd_sync(struct hci_dev *hdev, int err);

/* HCI device list */ LIST_HEAD(hci_dev_list); @@ -2695,6 +2696,8 @@ void hci_unregister_dev(struct hci_dev *hdev) hci_dev_set_flag(hdev, HCI_UNREGISTER); mutex_unlock(&hdev->unregister_lock);

+ hci_cancel_cmd_sync(hdev, EINTR); + write_lock(&hci_dev_list_lock); list_del(&hdev->list); write_unlock(&hci_dev_list_lock); @@ -2877,6 +2880,9 @@ int hci_resume_dev(struct hci_dev *hdev) ret = hci_resume_sync(hdev); hci_req_sync_unlock(hdev);

+ if (ret && hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return 0; + mgmt_resuming(hdev, hdev->wake_reason, &hdev->wake_addr, hdev->wake_addr_type);

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 6e76798ec786..f48d34fbfff2 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -174,10 +174,11 @@ struct sk_buff *__hci_cmd_sync_sk(struct hci_dev *hdev, u16 opcode, u32 plen, return ERR_PTR(err);

err = wait_event_interruptible_timeout(hdev->req_wait_q, - hdev->req_status != HCI_REQ_PEND, + hdev->req_status != HCI_REQ_PEND || + hci_dev_test_flag(hdev, HCI_UNREGISTER), timeout);

- if (err == -ERESTARTSYS) + if (err == -ERESTARTSYS || hci_dev_test_flag(hdev, HCI_UNREGISTER)) return ERR_PTR(-EINTR);

switch (hdev->req_status) { @@ -6296,6 +6297,7 @@ static int hci_resume_scan_sync(struct hci_dev *hdev) */ int hci_resume_sync(struct hci_dev *hdev) { + int err; /* If not marked as suspended there nothing to do */ if (!hdev->suspended) return 0; @@ -6303,10 +6305,14 @@ int hci_resume_sync(struct hci_dev *hdev) hdev->suspended = false;

/* Restore event mask */ - hci_set_event_mask_sync(hdev); + err = hci_set_event_mask_sync(hdev); + if (err && hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return err;

/* Clear any event filters and restore scan state */ - hci_clear_event_filter_sync(hdev); + err = hci_clear_event_filter_sync(hdev); + if (err && hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return err;

/* Resume scanning */ hci_resume_scan_sync(hdev); @@ -6315,10 +6321,14 @@ int hci_resume_sync(struct hci_dev *hdev) hci_resume_monitor_sync(hdev);

/* Resume other advertisements */ - hci_resume_advertising_sync(hdev); + err = hci_resume_advertising_sync(hdev); + if (err && hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return err;

/* Resume discovery */ - hci_resume_discovery_sync(hdev); + err = hci_resume_discovery_sync(hdev); + if (err && hci_dev_test_flag(hdev, HCI_UNREGISTER)) + return err;

return 0; }