[PATCH] mei: bus: type promotion bug in mei_nfc_if_version()

From: Dan Carpenter
Date: Wed Jul 04 2018 - 05:35:18 EST

We accidentally removed the check for negative returns without
considering the issue of type promotion. The "if_version_length"
variable is type size_t so if __mei_cl_recv() returns a negative then
"bytes_recv" is type promoted to a high positive value and treated as

Fixes: 582ab27a063a ("mei: bus: fix received data size check in NFC fixup")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 0208c4b027c5..fa0236a5e59a 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -267,7 +267,7 @@ static int mei_nfc_if_version(struct mei_cl *cl,

ret = 0;
bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, 0);
- if (bytes_recv < if_version_length) {
+ if (bytes_recv < 0 || bytes_recv < if_version_length) {
dev_err(bus->dev, "Could not read IF version\n");
ret = -EIO;
goto err;