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>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 36668d1..5ea7d51 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -63,6 +63,8 @@
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 @@
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 @@
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);