[PATCH 02/11] Bluetooth: btintel: Validate length before parsing diagnostics TLV

[Zijun Hu <zijun.hu@oss.qualcomm.com>]

btintel_diagnostics() accesses tlv->val[0] without first validating
that the diagnostics VSE is long enough to contain that field, so
may cause reading data beyond the received frame.

Fix by validating the length before access.

Fixes: af395330abed ("Bluetooth: btintel: Add Intel devcoredump support")
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
---
 drivers/bluetooth/btintel.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index d7baf1b9d852..dbcb3f138477 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -3766,16 +3766,19 @@ int btintel_configure_setup(struct hci_dev *hdev, const char *driver_name)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(btintel_configure_setup);
 
 static int btintel_diagnostics(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct intel_tlv *tlv = (void *)&skb->data[5];
 
+	if (skb->len < 5 + sizeof(*tlv) + sizeof(tlv->val[0]))
+		goto recv_frame;
+
 	/* The first event is always an event type TLV */
 	if (tlv->type != INTEL_TLV_TYPE_ID)
 		goto recv_frame;
 
 	switch (tlv->val[0]) {
 	case INTEL_TLV_SYSTEM_EXCEPTION:
 	case INTEL_TLV_FATAL_EXCEPTION:
 	case INTEL_TLV_DEBUG_EXCEPTION:

-- 
2.34.1