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
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
[bwh: Backported to 3.2:
- Drop inapplicable changes to hid_usage::usage_index initialisation and
to hid_report_raw_event()
- Adjust context in report_features()
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[yijingwang: Backported to 3.4: context adjust]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 9e3639e..daf4152 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -222,9 +222,9 @@
{
struct hid_report *report;
struct hid_field *field;
- int usages;
+ unsigned usages;
unsigned offset;
- int i;
+ unsigned i;
report = hid_register_report(parser->device, report_type, parser->global.report_id);
if (!report) {
@@ -244,7 +244,8 @@
if (!parser->local.usage_index) /* Ignore padding fields */
return 0;
- usages = max_t(int, parser->local.usage_index, parser->global.report_count);
+ usages = max_t(unsigned, parser->local.usage_index,
+ parser->global.report_count);
field = hid_register_field(report, usages, parser->global.report_count);
if (!field)
@@ -255,7 +256,7 @@
field->application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
for (i = 0; i < usages; i++) {
- int j = i;
+ unsigned j = i;
/* Duplicate the last usage we parsed if we have excess values */
if (i >= parser->local.usage_index)
j = parser->local.usage_index - 1;