5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ying Hsu <yinghsu@xxxxxxxxxxxx>
[ Upstream commit 2449007d3f73b2842c9734f45f0aadb522daf592 ]
While handling the HCI_EV_HARDWARE_ERROR event, if the underlying
BT controller is not responding, the GPIO reset mechanism would
free the hci_dev and lead to a use-after-free in hci_error_reset.
Here's the call trace observed on a ChromeOS device with Intel AX201:
queue_work_on+0x3e/0x6c
__hci_cmd_sync_sk+0x2ee/0x4c0 [bluetooth <HASH:3b4a6>]
? init_wait_entry+0x31/0x31
__hci_cmd_sync+0x16/0x20 [bluetooth <HASH:3b4a 6>]
hci_error_reset+0x4f/0xa4 [bluetooth <HASH:3b4a 6>]
process_one_work+0x1d8/0x33f
worker_thread+0x21b/0x373
kthread+0x13a/0x152
? pr_cont_work+0x54/0x54
? kthread_blkcg+0x31/0x31
ret_from_fork+0x1f/0x30
This patch holds the reference count on the hci_dev while processing
a HCI_EV_HARDWARE_ERROR event to avoid potential crash.
Fixes: c7741d16a57c ("Bluetooth: Perform a power cycle when receiving hardware error event")
Signed-off-by: Ying Hsu <yinghsu@xxxxxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/bluetooth/hci_core.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 54c55c30db17b..289fb28529f8c 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2272,6 +2272,7 @@ static void hci_error_reset(struct work_struct *work)
{
struct hci_dev *hdev = container_of(work, struct hci_dev, error_reset);
+ hci_dev_hold(hdev);
BT_DBG("%s", hdev->name);
if (hdev->hw_error)
@@ -2279,10 +2280,10 @@ static void hci_error_reset(struct work_struct *work)
else
bt_dev_err(hdev, "hardware error 0x%2.2x", hdev->hw_error_code);
- if (hci_dev_do_close(hdev))
- return;
+ if (!hci_dev_do_close(hdev))
+ hci_dev_do_open(hdev);
- hci_dev_do_open(hdev);
+ hci_dev_put(hdev);
}
void hci_uuids_clear(struct hci_dev *hdev)
--
2.43.0
