From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C5D1C64EAD for ; Sat, 29 Sep 2018 21:58:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49FEE206B8 for ; Sat, 29 Sep 2018 21:58:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49FEE206B8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728405AbeI3ES0 (ORCPT ); Sun, 30 Sep 2018 00:18:26 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51616 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727984AbeI3ESX (ORCPT ); Sun, 30 Sep 2018 00:18:23 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1g6N62-0000Gs-Sv; Sat, 29 Sep 2018 22:48:19 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1g6N5z-0006zI-V3; Sat, 29 Sep 2018 22:48:15 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jiri Kosina" , "Daniel Rosenberg" , "Benjamin Tissoires" Date: Sat, 29 Sep 2018 22:43:07 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 129/131] HID: debug: check length before copy_to_user() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.59-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Rosenberg commit 717adfdaf14704fd3ec7fa2c04520c0723247eac upstream. If our length is greater than the size of the buffer, we overflow the buffer Signed-off-by: Daniel Rosenberg Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina Signed-off-by: Ben Hutchings --- drivers/hid/hid-debug.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/hid/hid-debug.c +++ b/drivers/hid/hid-debug.c @@ -1150,6 +1150,8 @@ copy_rest: goto out; if (list->tail > list->head) { len = list->tail - list->head; + if (len > count) + len = count; if (copy_to_user(buffer + ret, &list->hid_debug_buf[list->head], len)) { ret = -EFAULT; @@ -1159,6 +1161,8 @@ copy_rest: list->head += len; } else { len = HID_DEBUG_BUFSIZE - list->head; + if (len > count) + len = count; if (copy_to_user(buffer, &list->hid_debug_buf[list->head], len)) { ret = -EFAULT; @@ -1166,7 +1170,9 @@ copy_rest: } list->head = 0; ret += len; - goto copy_rest; + count -= len; + if (count > 0) + goto copy_rest; } }