[PATCH 3.2 15/95] USB: idmouse: fix NULL-deref at probe

From: Ben Hutchings
Date: Sun Jul 16 2017 - 10:09:33 EST


3.2.91-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit b0addd3fa6bcd119be9428996d5d4522479ab240 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/misc/idmouse.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -346,6 +346,9 @@ static int idmouse_probe(struct usb_inte
if (iface_desc->desc.bInterfaceClass != 0x0A)
return -ENODEV;

+ if (iface_desc->desc.bNumEndpoints < 1)
+ return -ENODEV;
+
/* allocate memory for our device state and initialize it */
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev == NULL)