[PATCH 2/2] Bluetooth: btmtk: size the ISO receive skb to hold header plus payload
From: Chris Lu
Date: Tue Oct 13 2026 - 04:40:50 EST
btmtk_recv_isopkt() allocates HCI_MAX_ISO_SIZE (251) bytes and stores the
4-byte HCI ISO header into the same skb, leaving only 247 bytes for the
payload. A Data_Total_Length of 248..251 would fail the skb_tailroom()
check and be dropped with -EILSEQ, taking the rest of the URB transfer
with it.
HCI_MAX_ISO_SIZE is the maximum payload length, not the maximum frame
length, so allocate HCI_MAX_ISO_SIZE + HCI_ISO_HDR_SIZE, matching how the
ACL path uses HCI_MAX_FRAME_SIZE (HCI_MAX_ACL_SIZE + 4).
Fixes: ceac1cb0259d ("Bluetooth: btusb: mediatek: add ISO data transmission functions")
Co-developed-by: Hao Qin <hao.qin@xxxxxxxxxxxx>
Signed-off-by: Hao Qin <hao.qin@xxxxxxxxxxxx>
Co-developed-by: Wenlong Tian <ot_wenlong.tian@xxxxxxxxxxxx>
Signed-off-by: Wenlong Tian <ot_wenlong.tian@xxxxxxxxxxxx>
Signed-off-by: Chris Lu <chris.lu@xxxxxxxxxxxx>
---
drivers/bluetooth/btmtk.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c
index 869eb2176379..1b501b64d71f 100644
--- a/drivers/bluetooth/btmtk.c
+++ b/drivers/bluetooth/btmtk.c
@@ -1178,7 +1178,8 @@ static int btmtk_recv_isopkt(struct hci_dev *hdev, void *buffer, int count)
int len;
if (!skb) {
- skb = bt_skb_alloc(HCI_MAX_ISO_SIZE, GFP_ATOMIC);
+ skb = bt_skb_alloc(HCI_MAX_ISO_SIZE + HCI_ISO_HDR_SIZE,
+ GFP_ATOMIC);
if (!skb) {
err = -ENOMEM;
break;
--
2.45.2