HID: validate feature and input report details
commit cc6b54aa54bf40b762cab45a9fc8aa81653146eb upstream.
When dealing with usage_index, be sure to properly use unsigned instead of
int to avoid overflows.
When working on report fields, always validate that their report_counts are
in bounds.
Without this, a HID device could report a malicious feature report that
could trick the driver into a heap overflow:
[ 634.885003] usb 1-1: New USB device found, idVendor=0596, idProduct=0500
...
[ 676.469629] BUG kmalloc-192 (Tainted: G W ): Redzone overwritten
CVE-2013-2897
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index ac5e935..012880a 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -485,6 +485,10 @@
if (field->flags & HID_MAIN_ITEM_CONSTANT)
goto ignore;
+ /* Ignore if report count is out of bounds. */
+ if (field->report_count < 1)
+ goto ignore;
+
/* only LED usages are supported in output fields */
if (field->report_type == HID_OUTPUT_REPORT &&
(usage->hid & HID_USAGE_PAGE) != HID_UP_LED) {
@@ -1163,7 +1167,11 @@
rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
list_for_each_entry(rep, &rep_enum->report_list, list)
- for (i = 0; i < rep->maxfield; i++)
+ for (i = 0; i < rep->maxfield; i++) {
+ /* Ignore if report count is out of bounds. */
+ if (rep->field[i]->report_count < 1)
+ continue;
+
for (j = 0; j < rep->field[i]->maxusage; j++) {
/* Verify if Battery Strength feature is available */
hidinput_setup_battery(hid, HID_FEATURE_REPORT, rep->field[i]);
@@ -1172,6 +1180,7 @@
drv->feature_mapping(hid, rep->field[i],
rep->field[i]->usage + j);
}
+ }
}
static struct hid_input *hidinput_allocate(struct hid_device *hid)