HID: i2c-hid: allocate hid buffers for real worst case
authorAdrian Salido <salidoa@google.com>
Fri, 8 Sep 2017 17:55:27 +0000 (10:55 -0700)
committerJiri Kosina <jkosina@suse.cz>
Wed, 13 Sep 2017 16:16:40 +0000 (18:16 +0200)
The buffer allocation is not currently accounting for an extra byte for
the report id. This can cause an out of bounds access in function
i2c_hid_set_or_send_report() with reportID > 15.

Cc: stable@vger.kernel.org
Signed-off-by: Adrian Salido <salidoa@google.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/i2c-hid/i2c-hid.c

index 7739614..9145c21 100644 (file)
@@ -543,7 +543,8 @@ static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
 {
        /* the worst case is computed from the set_report command with a
         * reportID > 15 and the maximum report length */
-       int args_len = sizeof(__u8) + /* optional ReportID byte */
+       int args_len = sizeof(__u8) + /* ReportID */
+                      sizeof(__u8) + /* optional ReportID byte */
                       sizeof(__u16) + /* data register */
                       sizeof(__u16) + /* size of the report */
                       report_size; /* report */