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, 7 insertions, 3 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 36668d1aca8f..5ea7d51e45b9 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -63,6 +63,8 @@ struct hid_report *hid_register_report(struct hid_device *device, unsigned type,
         struct hid_report_enum *report_enum = device->report_enum + type;
         struct hid_report *report;
 
+        if (id >= HID_MAX_IDS)
+                return NULL;
         if (report_enum->report_id_hash[id])
                 return report_enum->report_id_hash[id];
 
@@ -404,8 +406,10 @@ static int hid_parser_global(struct hid_parser *parser, struct hid_item *item)
 
         case HID_GLOBAL_ITEM_TAG_REPORT_ID:
                 parser->global.report_id = item_udata(item);
-                if (parser->global.report_id == 0) {
-                        hid_err(parser->device, "report_id 0 is invalid\n");
+                if (parser->global.report_id == 0 ||
+                    parser->global.report_id >= HID_MAX_IDS) {
+                        hid_err(parser->device, "report_id %u is invalid\n",
+                                parser->global.report_id);
                         return -1;
                 }
                 return 0;
@@ -575,7 +579,7 @@ static void hid_close_report(struct hid_device *device)
         for (i = 0; i < HID_REPORT_TYPES; i++) {
                 struct hid_report_enum *report_enum = device->report_enum + i;
 
-                for (j = 0; j < 256; j++) {
+                for (j = 0; j < HID_MAX_IDS; j++) {
                         struct hid_report *report = report_enum->report_id_hash[j];
                         if (report)
                                 hid_free_report(report);