From patchwork Wed Aug 18 06:05:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 12443265 X-Patchwork-Delegate: johannes@sipsolutions.net 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 A1C32C4320A for ; Wed, 18 Aug 2021 06:24:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BA9961056 for ; Wed, 18 Aug 2021 06:24:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238961AbhHRGYw (ORCPT ); Wed, 18 Aug 2021 02:24:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238445AbhHRGYs (ORCPT ); Wed, 18 Aug 2021 02:24:48 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1973AC0613A4 for ; Tue, 17 Aug 2021 23:24:14 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id m24-20020a17090a7f98b0290178b1a81700so1627990pjl.4 for ; Tue, 17 Aug 2021 23:24:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wNrSyu18+TQvxqozBk6dKmc83xjPuqXEkZM9+CZkQs8=; b=hq0RZc8pvhUdG6LQCrGBNQbN7VTMq2CkOF4QQtsj4WrxV2UTBN34Md8Gi7LkipMBy6 xL7jSFJnNHOowLO3Jca2aK8bMlaJLC+laeAIEoH1LMm2sWoMULTrkMcKoRbBAsM8UOpd ihsdkkeDmGTdleDP1YZNWHcSi4UiGfzn3DsyI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wNrSyu18+TQvxqozBk6dKmc83xjPuqXEkZM9+CZkQs8=; b=tCEqCBLlDIDKsVcVdw7pQtPM2OBh4xQ5TMrSmXQRx3/0GRQNoiwTmpCp3ZF/GJ5ALI hPNhpy5BvPJuxrO1nRC33A6xD/dP6wmGKNN2BKq9t/4kGJaqNliwuveC3FiDCMq7Ajsr wz8T9MMwCieCYSu47ZD6RUWDXN15nVmUXcywUZU0TvdxMpHdIvJWm1xA2Xg71VyXdZc2 K/7hs5Q34L0MpRPNGkoOsj1g1Hi8O9y/DnLRXAjvumji9/QEr4ID84FFwH7VGta6+bxM VNOxi3eyc1UX60xGLXNrFvZaPOzz1oFqnndcDqmt4ldmfLljwWyhfzVV1mGUD97jJYyd pL/Q== X-Gm-Message-State: AOAM532BU39etg+fRnikqG14E//iIGoxKrcvvIRUWbyo/9EG6xoO/toZ AFVjjymfg2qH/Px7Z2Ewc+/d4A== X-Google-Smtp-Source: ABdhPJxMkEdSe0VUFwn+z4vxkdsUFqJ2UwImPieDkAd2A7unXagJo2uR8zh40lbVDVJdC8iJXw8UiA== X-Received: by 2002:a17:902:cec3:b0:12d:92c4:1ea6 with SMTP id d3-20020a170902cec300b0012d92c41ea6mr5911733plg.36.1629267853392; Tue, 17 Aug 2021 23:24:13 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id y13sm2710073pjr.50.2021.08.17.23.24.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 23:24:12 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, "Gustavo A. R. Silva" , Greg Kroah-Hartman , Andrew Morton , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-staging@lists.linux.dev, linux-block@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com, Rasmus Villemoes , linux-hardening@vger.kernel.org Subject: [PATCH v2 49/63] btrfs: Use memset_startat() to clear end of struct Date: Tue, 17 Aug 2021 23:05:19 -0700 Message-Id: <20210818060533.3569517-50-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210818060533.3569517-1-keescook@chromium.org> References: <20210818060533.3569517-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1202; h=from:subject; bh=j07ODF9kjbRRiHohObgJ1N/RHPZCTrQAmspnQvku4YA=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBhHKMpNf/1TOA8EHO13yPM2WoVQcddjcJSpXNg/q95 NGD5Kx+JAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYRyjKQAKCRCJcvTf3G3AJiFDD/ 43YRq8chsycAfEPzeH3ODP8oX8vzyejO0KZxGwB29jISLONkndclAADo87JB841bplfSqHF4g/N0Yr 9BPUFM/u9aD6MYInBsgRcfvidkMVdvLwJHJroTXouReKf+wENJpCE42XqDFb6/OHW+qszfq48l2ZsZ vlrJcOJH5B/7MGz2vGlPOqarS6QPhKxELyHgWma5US/BF+fmqXoGyLI96PzJHBVwD8Fv1vRW+FZyYX mS0c778XSYdo50TMLiLEeybc58/w6WbytsuOe2gDRaDra0L+tnQU3bUemlEwF/otdXngLgjznL3aHr 03wBbU/uuuYnsF2VxKSH3eTmyOXxM0Fc0gfhMAHlPYOx3FWaj25UujliZBiwYTeajzJsMlNaMxhyYC CNKnLKNfyeqkcnmjrNFG0fLVNoy2o0OR5zMuoedsu9e9ywbM82GfxRkHbOU9ZMZ5GgY2NMQXjzSHXm JS7ECNId/+w48q42Qz1RDDbkk71kX5clz/7ywEULnxcdaVF9VLida+SAjBnEmtDTTT5a3LFsbnweA7 31UgpReo5DWgV9+9dvXi/NGJgP+uufVyB7FGtNrTHKNpqkfmCVfC6YFh7uVwrtuLat1U/8LUy3Rdgf RT0NM3pRRzNQ/fI9ZSg5+8wsIv5qwbvYlgUlhc046qXy22//QbKOPQkqvAQQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Use memset_startat() so memset() doesn't get confused about writing beyond the destination member that is intended to be the starting point of zeroing through the end of the struct. Cc: Chris Mason Cc: Josef Bacik Cc: David Sterba Cc: linux-btrfs@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Nikolay Borisov Acked-by: David Sterba --- fs/btrfs/root-tree.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 702dc5441f03..12ceb14a1141 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -39,10 +39,8 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot, need_reset = 1; } if (need_reset) { - memset(&item->generation_v2, 0, - sizeof(*item) - offsetof(struct btrfs_root_item, - generation_v2)); - + /* Clear all members from generation_v2 onwards. */ + memset_startat(item, 0, generation_v2); generate_random_guid(item->uuid); } }