HID: validate HID report id size

The "Report ID" field of a HID report is used to build indexes of
reports. The kernel's index of these is limited to 256 entries, so any
malicious device that sets a Report ID greater than 255 will trigger
memory corruption on the host:

[ 1347.156239] BUG: unable to handle kernel paging request at ffff88094958a878
[ 1347.156261] IP: [<ffffffff813e4da0>] hid_register_report+0x2a/0x8b

CVE-2013-2888

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 0c48991b0402..ff545cc33c3a 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -393,10 +393,12 @@ struct hid_report {
         struct hid_device *device;                      /* associated device */
 };
 
+#define HID_MAX_IDS 256
+
 struct hid_report_enum {
         unsigned numbered;
         struct list_head report_list;
-        struct hid_report *report_id_hash[256];
+        struct hid_report *report_id_hash[HID_MAX_IDS];
 };
 
 #define HID_REPORT_TYPES 3