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authorKees Cook <keescook@chromium.org>2013-08-28 22:29:55 +0200
committerJiri Kosina <jkosina@suse.cz>2013-08-29 11:01:25 +0200
commit43622021d2e2b82ea03d883926605bdd0525e1d1 (patch)
treeeb347fb9b63e544151787d58f8940bdd957961a0 /drivers/hid
parent58c59bc997d86593f0bea41845885917cf304d22 (diff)
downloadblackbird-op-linux-43622021d2e2b82ea03d883926605bdd0525e1d1.tar.gz
blackbird-op-linux-43622021d2e2b82ea03d883926605bdd0525e1d1.zip
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>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/hid-core.c10
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);
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