This is a note to let you know that I've just added the patch titled
usb: rndis_host: Secure rndis_query check against int overflow
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-rndis_host-secure-rndis_query-check-against-int-.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 222ef43d7b1aa8025766444d3cdefd14761c0a87
Author: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
Date: Tue Jan 3 10:17:09 2023 +0100
usb: rndis_host: Secure rndis_query check against int overflow
[ Upstream commit c7dd13805f8b8fc1ce3b6d40f6aff47e66b72ad2 ]
Variables off and len typed as uint32 in rndis_query function
are controlled by incoming RNDIS response message thus their
value may be manipulated. Setting off to a unexpectetly large
value will cause the sum with len and 8 to overflow and pass
the implemented validation step. Consequently the response
pointer will be referring to a location past the expected
buffer boundaries allowing information leakage e.g. via
RNDIS_OID_802_3_PERMANENT_ADDRESS OID.
Fixes: ddda08624013 ("USB: rndis_host, various cleanups")
Signed-off-by: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c
index ab41a63aa4aa..497d6bcdc276 100644
--- a/drivers/net/usb/rndis_host.c
+++ b/drivers/net/usb/rndis_host.c
@@ -267,7 +267,8 @@ static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
off = le32_to_cpu(u.get_c->offset);
len = le32_to_cpu(u.get_c->len);
- if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
+ if (unlikely((off > CONTROL_BUFFER_SIZE - 8) ||
+ (len > CONTROL_BUFFER_SIZE - 8 - off)))
goto response_error;
if (*reply_len != -1 && len != *reply_len)
