[PATCH] USB: rndis: Fix for handling garbled messages

From: Phil Edworthy
Date: Thu May 10 2018 - 09:09:22 EST


From: Michel Pollet <michel.pollet@xxxxxxxxxxxxxx>

A message can be forged to crash the stack; here we make sure we don't
completely break the system if this occurs

Signed-off-by: Michel Pollet <michel.pollet@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/rndis.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 51dd3e9..04c142c 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -851,6 +851,9 @@ int rndis_msg_parser(struct rndis_params *params, u8 *buf)
*/
pr_warn("%s: unknown RNDIS message 0x%08X len %d\n",
__func__, MsgType, MsgLength);
+ /* Garbled message can be huge, so limit what we display */
+ if (MsgLength > 16)
+ MsgLength = 16;
print_hex_dump_bytes(__func__, DUMP_PREFIX_OFFSET,
buf, MsgLength);
break;
--
2.7.4