[PATCH 1/2] usb: gadget: function: rndis: add length check to response query

[Griffin Kroah-Hartman]

Add variable representations for BufLength and BufOffset in
rndis_query_response(), and perform a length check on them.

This is identical to how rndis_set_response() handles these parameters.

Assisted-by: gkh_clanker_2000
Signed-off-by: Griffin Kroah-Hartman <griffin@xxxxxxxxx>
---
 drivers/usb/gadget/function/rndis.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 3da54a7d7aba..fe2018ff071a 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -591,6 +591,7 @@ static int rndis_init_response(struct rndis_params *params,
 static int rndis_query_response(struct rndis_params *params,
 				rndis_query_msg_type *buf)
 {
+	u32 BufLength, BufOffset;
 	rndis_query_cmplt_type *resp;
 	rndis_resp_t *r;
 
@@ -598,6 +599,13 @@ static int rndis_query_response(struct rndis_params *params,
 	if (!params->dev)
 		return -ENOTSUPP;
 
+	BufLength = le32_to_cpu(buf->InformationBufferLength);
+	BufOffset = le32_to_cpu(buf->InformationBufferOffset);
+	if ((BufLength > RNDIS_MAX_TOTAL_SIZE) ||
+	    (BufOffset > RNDIS_MAX_TOTAL_SIZE) ||
+	    (BufOffset + 8 >= RNDIS_MAX_TOTAL_SIZE))
+		return -EINVAL;
+
 	/*
 	 * we need more memory:
 	 * gen_ndis_query_resp expects enough space for
@@ -614,10 +622,8 @@ static int rndis_query_response(struct rndis_params *params,
 	resp->RequestID = buf->RequestID; /* Still LE in msg buffer */
 
 	if (gen_ndis_query_resp(params, le32_to_cpu(buf->OID),
-			le32_to_cpu(buf->InformationBufferOffset)
-					+ 8 + (u8 *)buf,
-			le32_to_cpu(buf->InformationBufferLength),
-			r)) {
+				BufOffset + 8 + (u8 *)buf,
+				BufLength, r)) {
 		/* OID not supported */
 		resp->Status = cpu_to_le32(RNDIS_STATUS_NOT_SUPPORTED);
 		resp->MessageLength = cpu_to_le32(sizeof *resp);

-- 
2.55.0