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authorKees Cook <keescook@chromium.org>2013-08-28 22:29:55 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-26 16:52:48 -0700
commit645c9dcabb2c234e6d4a546125830d04988a1f90 (patch)
tree8c05df876f1aacd5bf41cff68bdfb29318952a42
parentc993386d8c99c60ffb1161076040f3ffb46c0794 (diff)
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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.c12
-rw-r--r--include/linux/hid.h4
2 files changed, 11 insertions, 5 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 53576e7..bc0bb21 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 42f7e2f..af30c64 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