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>
This commit is contained in:
Kees Cook 2013-08-28 22:29:55 +02:00 committed by Jiri Kosina
parent 58c59bc997
commit 43622021d2
2 changed files with 10 additions and 4 deletions

View File

@ -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);

View File

@ -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