From patchwork Thu Apr 22 20:00:32 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: 426641 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=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 A7F75C433ED for ; Thu, 22 Apr 2021 20:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69FFD61437 for ; Thu, 22 Apr 2021 20:00:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239066AbhDVUAq (ORCPT ); Thu, 22 Apr 2021 16:00:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:53544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236058AbhDVUAp (ORCPT ); Thu, 22 Apr 2021 16:00:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 12E126100B; Thu, 22 Apr 2021 20:00:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619121609; bh=f/P+1/0wMQTXhtxadIAI7KmLHWPPdlXhjk/DweX0UbQ=; h=Date:From:To:Cc:Subject:From; b=rfEbGF7maHCbOROn8ePxnwH8t94xIoe2A4oyzoJbeH0JXeGokZScZ8S757OVSfzSh PXMRAoY9tvwBe1iYHxaSJ7q3Djs0dQcg9jZXZJXRnSwSUvJ/QVru7y2CfIIRxN8htR SXpT1GUtxaq12aPNUFqCSW8Ir75dGE0GRatucZpYP97bhAQX1LlInV7bs04O/+9ipT p7U0caxepGRb7pZTJJqdXEDii5FuVrYRX75WC+Rvqlm0KAb2WIrWt+dgz2jg7VCgRM 4DG+88NKuFqQ9w3ssbrBh1vu6Cu5ksApx44vHTzq4juYvV2WmuuOj9ds14di6ipf9S DpfU9PLAiluqQ== Date: Thu, 22 Apr 2021 15:00:32 -0500 From: "Gustavo A. R. Silva" To: Johannes Berg , "David S. Miller" , Jakub Kicinski Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org, Kees Cook Subject: [PATCH v2][next] wireless: wext-spy: Fix out-of-bounds warning Message-ID: <20210422200032.GA168995@embeddedor> MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Fix the following out-of-bounds warning: net/wireless/wext-spy.c:178:2: warning: 'memcpy' offset [25, 28] from the object at 'threshold' is out of the bounds of referenced subobject 'low' with type 'struct iw_quality' at offset 20 [-Warray-bounds] The problem is that the original code is trying to copy data into a couple of struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &threshold.low and &spydata->spy_thr_low. As these are just a couple of struct members, fix this by using direct assignments, instead of memcpy(). 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 Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Use direct struct assignments instead of memcpy(). - Fix one more instance of this same issue in function iw_handler_get_thrspy(). - Update changelog text. - Add Kees' RB tag. net/wireless/wext-spy.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/wireless/wext-spy.c b/net/wireless/wext-spy.c index 33bef22e44e9..b379a0371653 100644 --- a/net/wireless/wext-spy.c +++ b/net/wireless/wext-spy.c @@ -120,8 +120,8 @@ int iw_handler_set_thrspy(struct net_device * dev, return -EOPNOTSUPP; /* Just do it */ - memcpy(&(spydata->spy_thr_low), &(threshold->low), - 2 * sizeof(struct iw_quality)); + spydata->spy_thr_low = threshold->low; + spydata->spy_thr_high = threshold->high; /* Clear flag */ memset(spydata->spy_thr_under, '\0', sizeof(spydata->spy_thr_under)); @@ -147,8 +147,8 @@ int iw_handler_get_thrspy(struct net_device * dev, return -EOPNOTSUPP; /* Just do it */ - memcpy(&(threshold->low), &(spydata->spy_thr_low), - 2 * sizeof(struct iw_quality)); + threshold->low = spydata->spy_thr_low; + threshold->high = spydata->spy_thr_high; return 0; } @@ -173,10 +173,10 @@ static void iw_send_thrspy_event(struct net_device * dev, memcpy(threshold.addr.sa_data, address, ETH_ALEN); threshold.addr.sa_family = ARPHRD_ETHER; /* Copy stats */ - memcpy(&(threshold.qual), wstats, sizeof(struct iw_quality)); + threshold.qual = *wstats; /* Copy also thresholds */ - memcpy(&(threshold.low), &(spydata->spy_thr_low), - 2 * sizeof(struct iw_quality)); + threshold.low = spydata->spy_thr_low; + threshold.high = spydata->spy_thr_high; /* Send event to user space */ wireless_send_event(dev, SIOCGIWTHRSPY, &wrqu, (char *) &threshold);