From e3ac0d9f1a205f33a43fba3b79ef74d2f604c78b Mon Sep 17 00:00:00 2001 From: Pauli Virtanen Date: Fri, 24 Apr 2026 22:24:29 +0300 Subject: [PATCH] Bluetooth: btmtk: accept too short WMT FUNC_CTRL events MT7925 (USB ID 0e8d:e025) on fw version 20260106153314 sends WMT FUNC_CTRL events that are missing the status field. Prior to commit 006b9943b982 ("Bluetooth: btmtk: validate WMT event SKB length before struct access") the status was read from out-of-bounds of SKB data, which usually would result to success with BTMTK_WMT_ON_UNDONE, although I don't know the intent here. The bounds check added in that commit returns with error instead, producing "Bluetooth: hci0: Failed to send wmt func ctrl (-22)" and makes the device unusable. Fix the regression by interpreting too short packet as status BTMTK_WMT_ON_UNDONE, which makes the device work normally again. Fixes: 634a4408c061 ("Bluetooth: btmtk: validate WMT event SKB length before struct access") Signed-off-by: Pauli Virtanen Tested-by: Mikhail Gavrilov # MT7922 (0489:e0e2) Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btmtk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c index f70c1b0f8990..a29f72216c34 100644 --- a/drivers/bluetooth/btmtk.c +++ b/drivers/bluetooth/btmtk.c @@ -719,8 +719,8 @@ static int btmtk_usb_hci_wmt_sync(struct hci_dev *hdev, case BTMTK_WMT_FUNC_CTRL: if (!skb_pull_data(data->evt_skb, sizeof(wmt_evt_funcc->status))) { - err = -EINVAL; - goto err_free_skb; + status = BTMTK_WMT_ON_UNDONE; + break; } wmt_evt_funcc = (struct btmtk_hci_wmt_evt_funcc *)wmt_evt;