[PATCH v2] Bluetooth: hci_h4: Fix padding calculation error within h4_recv_buf()

From: Zijun Hu
Date: Tue Nov 16 2021 - 03:52:32 EST


From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>

it is erroneous to calculate padding by subtracting length of type
indication from skb->len, it will cause data analysis error for
alignment which is greater than 1, so fixed by adding length of type
indication with skb->len.

Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
drivers/bluetooth/hci_h4.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_h4.c b/drivers/bluetooth/hci_h4.c
index 4b3b14a34794..1d0cdf023243 100644
--- a/drivers/bluetooth/hci_h4.c
+++ b/drivers/bluetooth/hci_h4.c
@@ -252,7 +252,7 @@ struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
}

if (!dlen) {
- hu->padding = (skb->len - 1) % alignment;
+ hu->padding = (skb->len + 1) % alignment;
hu->padding = (alignment - hu->padding) % alignment;

/* No more data, complete frame */
@@ -260,7 +260,7 @@ struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
skb = NULL;
}
} else {
- hu->padding = (skb->len - 1) % alignment;
+ hu->padding = (skb->len + 1) % alignment;
hu->padding = (alignment - hu->padding) % alignment;

/* Complete frame */
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project