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 16:52:48 -0700 |
| commit | 645c9dcabb2c234e6d4a546125830d04988a1f90 (patch) | |
| tree | 8c05df876f1aacd5bf41cff68bdfb29318952a42 | |
| parent | c993386d8c99c60ffb1161076040f3ffb46c0794 (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 | 12 | ||||
| -rw-r--r-- | include/linux/hid.h | 4 |
2 files changed, 11 insertions, 5 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 53576e7c8bc..bc0bb213e77 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -58,6 +58,8 @@ 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]; @@ -379,9 +381,11 @@ 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) { - dbg_hid("report_id 0 is invalid\n"); - return -1; + 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; @@ -551,7 +555,7 @@ 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 42f7e2fb501..af30c6412ad 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -414,10 +414,12 @@ 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 |