Malicious USB devices can send bogus reports smaller than the expected
buffer size. Ensure that the length is valid to avoid reading out of
bounds.

Signed-off-by: Peter Wu <pe...@lekensteyn.nl>
---
 v1: patch 2/3 HID: logitech-{dj,hidpp}: check report length
 v2: splitted original report length check patch
---
 drivers/hid/hid-logitech-dj.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index c917ab6..5bc6d80 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -962,10 +962,24 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 
        switch (data[0]) {
        case REPORT_ID_DJ_SHORT:
+               if (size != DJREPORT_SHORT_LENGTH) {
+                       dev_err(&hdev->dev, "DJ report of bad size (%d)", size);
+                       return false;
+               }
                return logi_dj_dj_event(hdev, report, data, size);
        case REPORT_ID_HIDPP_SHORT:
-               /* intentional fallthrough */
+               if (size != HIDPP_REPORT_SHORT_LENGTH) {
+                       dev_err(&hdev->dev,
+                               "Short HID++ report of bad size (%d)", size);
+                       return false;
+               }
+               return logi_dj_hidpp_event(hdev, report, data, size);
        case REPORT_ID_HIDPP_LONG:
+               if (size != HIDPP_REPORT_LONG_LENGTH) {
+                       dev_err(&hdev->dev,
+                               "Long HID++ report of bad size (%d)", size);
+                       return false;
+               }
                return logi_dj_hidpp_event(hdev, report, data, size);
        }
 
-- 
2.1.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to