From patchwork Fri Apr 16 20:15:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 423747 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=-21.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 12564C433B4 for ; Fri, 16 Apr 2021 20:15:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7FDB613C5 for ; Fri, 16 Apr 2021 20:15:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244908AbhDPUPy (ORCPT ); Fri, 16 Apr 2021 16:15:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:44866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235769AbhDPUPx (ORCPT ); Fri, 16 Apr 2021 16:15:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E6A4F613CD; Fri, 16 Apr 2021 20:15:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618604128; bh=tP9b6iJ1JpH4vs7bJWhEYStqEIRGGBbyJmBHWGu7Qpw=; h=Date:From:To:Cc:Subject:From; b=Jh2zRsPLwXzeBxS2b6vlrjjcPT4MVQDsuJp8EwiUnGQnf9DS/UQWDCiMJPqmYSyZB wVnd+EMStsDyWlPVx+XcqGQWESrPvrfThM0QTrAd29RVLaTbZxJrPDU3BqkMfB0oNn QrJi2GQrtI0a7fD82Tdon5gYfOSPW3ekfnh5bIPvM1jnNWZcMh0Eqn1UF9OBbSHQOd DBXuLM0UAhw3k41t1VT8fKvezboIloODGAyiOJGFHTkIZlueejLHc4kePsVqOP4FfS mKOZQTm5hQbnUqD521qZihl0+1G6QvRxcyVEUjTqUH43fluXMhF5ivlwGyPbhLXxt/ CRXyjWRA40xyA== Date: Fri, 16 Apr 2021 15:15:40 -0500 From: "Gustavo A. R. Silva" To: "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] ethtool: ioctl: Fix out-of-bounds warning in store_link_ksettings_for_user() Message-ID: <20210416201540.GA593906@embeddedor> MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Fix the following out-of-bounds warning: net/ethtool/ioctl.c:492:2: warning: 'memcpy' offset [49, 84] from the object at 'link_usettings' is out of the bounds of referenced subobject 'base' with type 'struct ethtool_link_settings' at offset 0 [-Warray-bounds] The problem is that the original code is trying to copy data into a some struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &link_usettings.base. Fix this by directly using &link_usettings and _from_ as destination and source addresses, instead. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot Signed-off-by: Gustavo A. R. Silva --- net/ethtool/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 27f1c5224acb..3fa7a394eabf 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -489,7 +489,7 @@ store_link_ksettings_for_user(void __user *to, { struct ethtool_link_usettings link_usettings; - memcpy(&link_usettings.base, &from->base, sizeof(link_usettings)); + memcpy(&link_usettings, from, sizeof(link_usettings)); bitmap_to_arr32(link_usettings.link_modes.supported, from->link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NBITS);