wifi: wfx: prevent underflow in wfx_send_pds()

This does a "chunk_len - 4" subtraction later when it calls:

	ret = wfx_hif_configuration(wdev, buf + 4, chunk_len - 4);

so check for "chunk_len" is less than 4.

Fixes: dcbecb4979 ("staging: wfx: allow new PDS format")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/Yv8eX7Xv2ubUOvW7@kili
This commit is contained in:
Dan Carpenter 2022-08-19 08:23:43 +03:00 committed by Kalle Valo
parent 620d5eaeb9
commit f97c81f5b7

View File

@ -181,7 +181,7 @@ int wfx_send_pds(struct wfx_dev *wdev, u8 *buf, size_t len)
while (len > 0) {
chunk_type = get_unaligned_le16(buf + 0);
chunk_len = get_unaligned_le16(buf + 2);
if (chunk_len > len) {
if (chunk_len < 4 || chunk_len > len) {
dev_err(wdev->dev, "PDS:%d: corrupted file\n", chunk_num);
return -EINVAL;
}