[PATCH 4.14 36/44] usb: gadget: rndis: check size of RNDIS_MSG_SET command

Greg Kroah-Hartman
2022-02-14T09:34:02Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 38ea1eac7d88072bbffb630e2b3db83ca649b826 upstream.

Check the size of the RNDIS_MSG_SET command given to us before
attempting to respond to an invalid message size.

Reported-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Cc: stable@kernel.org
Tested-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/gadget/function/rndis.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -640,14 +640,17 @@ static int rndis_set_response(struct rnd
rndis_set_cmplt_type *resp;
rndis_resp_t *r;

+ BufLength = le32_to_cpu(buf->InformationBufferLength);
+ BufOffset = le32_to_cpu(buf->InformationBufferOffset);
+ if ((BufLength > RNDIS_MAX_TOTAL_SIZE) ||
+ (BufOffset + 8 >= RNDIS_MAX_TOTAL_SIZE))
+ return -EINVAL;
+
r = rndis_add_response(params, sizeof(rndis_set_cmplt_type));
if (!r)
return -ENOMEM;
resp = (rndis_set_cmplt_type *)r->buf;

- BufLength = le32_to_cpu(buf->InformationBufferLength);
- BufOffset = le32_to_cpu(buf->InformationBufferOffset);
-
#ifdef VERBOSE_DEBUG
pr_debug("%s: Length: %d\n", __func__, BufLength);
pr_debug("%s: Offset: %d\n", __func__, BufOffset);