HID: validate HID report id size

commit 43622021d2e2b82ea03d883926605bdd0525e1d1 upstream.

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>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 10 insertions, 4 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 402f48689943..eb202481fb09 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);
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