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Commit 43622021 authored by Kees Cook's avatar Kees Cook Committed by Jiri Kosina
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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: default avatarKees Cook <keescook@chromium.org>
Cc: stable@kernel.org
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 58c59bc9

drivers/hid/hid-core.c

+7 −3
Original line number Diff line number Diff line
@@ -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);

include/linux/hid.h

+3 −1
Original line number Diff line number Diff line
@@ -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