[PATCH 5.19 227/717] wifi: wfx: prevent underflow in wfx_send_pds()

Greg Kroah-Hartman
2022-10-22T07:58:24Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit f97c81f5b7f8047810b0d79a8f759a83951210a0 ]

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: dcbecb497908 ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/silabs/wfx/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/silabs/wfx/main.c b/drivers/net/wireless/silabs/wfx/main.c
index e015bfb8d221..84d82ddded56 100644
--- a/drivers/net/wireless/silabs/wfx/main.c
+++ b/drivers/net/wireless/silabs/wfx/main.c
@@ -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;
}
--
2.35.1