[PATCH 73/93] HID: sensor-hub: validate feature report details

[Kamal Mostafa]

3.8.13.10 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook at chromium.org>

commit 9e8910257397372633e74b333ef891f20c800ee4 upstream.

A HID device could send a malicious feature report that would cause the
sensor-hub HID driver to read past the end of heap allocation, leaking
kernel memory contents to the caller.

CVE-2013-2898

Signed-off-by: Kees Cook <keescook at chromium.org>
Reviewed-by: Mika Westerberg <mika.westerberg at linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/hid/hid-sensor-hub.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 0bc58bd..5dfcf43 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -223,7 +223,8 @@ int sensor_hub_get_feature(struct hid_sensor_hub_device *hsdev, u32 report_id,
 
 	mutex_lock(&data->mutex);
 	report = sensor_hub_report(report_id, hsdev->hdev, HID_FEATURE_REPORT);
-	if (!report || (field_index >=  report->maxfield)) {
+	if (!report || (field_index >=  report->maxfield) ||
+	    report->field[field_index]->report_count < 1) {
 		ret = -EINVAL;
 		goto done_proc;
 	}
-- 
1.8.1.2