diff options
| author | Kees Cook <keescook@chromium.org> | 2013-08-28 22:29:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-26 17:15:34 -0700 |
| commit | 676bb9a417ceec66576daeb24aed2184a82ef544 (patch) | |
| tree | 0fe1e2fc2906db54dd98ffd118a4dd94be056a2e | |
| parent | 355c557b3e0164eaf75aded30e92da5a3a818c5f (diff) | |
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>
| -rw-r--r-- | drivers/hid/hid-core.c | 10 | ||||
| -rw-r--r-- | include/linux/hid.h | 4 |
2 files changed, 10 insertions, 4 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index ff73d60cfc7f..228c8495e97f 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]; @@ -385,8 +387,10 @@ 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; @@ -557,7 +561,7 @@ static void hid_device_release(struct device *dev) 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 3a95da60fd3e..8c933a86cba9 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -420,10 +420,12 @@ 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 |