HID: logitech-hidpp: add boundary check for name retrieval

The HID response has a limited size. Do not trust the value returned by
hardware, check that it really fits in the message.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 4d72c20fa233..4292cc33c119 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -313,6 +313,9 @@ static char *hidpp_get_unifying_name(struct hidpp_device *hidpp_dev)
 
         len = response.rap.params[1];
 
+        if (2 + len > sizeof(response.rap.params))
+                return NULL;
+
         name = kzalloc(len + 1, GFP_KERNEL);
         if (!name)
                 return NULL;