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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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_IN_DEF_DKIM_WL 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 3E43FC4320A for ; Wed, 4 Aug 2021 08:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20F46610A2 for ; Wed, 4 Aug 2021 08:41:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236654AbhHDIlv (ORCPT ); Wed, 4 Aug 2021 04:41:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235307AbhHDIlu (ORCPT ); Wed, 4 Aug 2021 04:41:50 -0400 Received: from mail-ot1-x335.google.com (mail-ot1-x335.google.com [IPv6:2607:f8b0:4864:20::335]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3E75C0613D5 for ; Wed, 4 Aug 2021 01:41:37 -0700 (PDT) Received: by mail-ot1-x335.google.com with SMTP id 61-20020a9d0d430000b02903eabfc221a9so1043356oti.0 for ; Wed, 04 Aug 2021 01:41:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ry/C788Ax+QRjoem679Qz9xjcGp3R8vxYXF3Ug8T/cU=; b=CdeSijkPZlqUImGIAEzCPBTp6l7WQasuELwBXyk/ZoG5VDeh1gjR+9z3QgEETkKMXx ESlpE0ZjQ6Hm4EczMgQduF7lq//myVLatAB4ctFpbLT5+96N383jrCYI+6OROefnr406 vQk/G+owiXqx6JVCRyqvTddr/+DGhRXI+vd61ALTEzm5pGxtmfJp9fAHE+I7gsVluHKn HzgA76R4usQfRo5H8GM4t39wQzbxhwP7HYrKHuoMo1v4E8IHXBPydAKh5qHaWXy8oW+Y J+Qikv9yXbG5K5ClLtSz4jV/dOrpGWZf0sJpFAB0kWfvC8KHFw9VjvZb5H7RQw8e0C6m s+2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Ry/C788Ax+QRjoem679Qz9xjcGp3R8vxYXF3Ug8T/cU=; b=jYb7ghB0yR2qdjGm9dJ4LswTw6gvlWFSQ1fIvsVxtHMMa9ntf199xJYZwd68EFj6ni upVwoxqgXRyY56Gh6yCg0sKb+CyAYiXGS6gi0N6urkMTg9feV9WvfTOhnTvOP9xwHjsD FMCJM5zR/neehnTyQxQ1Pm/gtl8F8Fi/pQz0ohy560OkmaqBGUlc/9XVoyA3+e5Kn9yb 8Und0LV/u4VTOU+OzOXhspMmLDG/xoHdIM39SG3CwYi+LM3RqTYdnHvPJ0htxryOJ0HS IMI25msVYbMeg/al3M8o51FIn2MaZ01VFn+jNUsX0Eu7nK93J18LLjsb+tNW/roX2Ngm SS7w== X-Gm-Message-State: AOAM531Oq3UwDIvAGrwmKRoh6Us2/YTrdCHldpe/6/lNiUCRAgMdwdA+ JfoEYo84hBp8tKdbiX3yoJV6f4gD/RnwOLmBuIi73A== X-Google-Smtp-Source: ABdhPJwULOwQJrId2LR6uf4OqnUiOnC6+yQnX9X5/0EP+lRGGxsuaAeYFWMZ2K7UDJwoWl0nMWJTt4uXnmlICOmyUos= X-Received: by 2002:a05:6830:1490:: with SMTP id s16mr2295783otq.233.1628066496794; Wed, 04 Aug 2021 01:41:36 -0700 (PDT) MIME-Version: 1.0 References: <20210804082230.10837-1-Kuan-Ying.Lee@mediatek.com> <20210804082230.10837-3-Kuan-Ying.Lee@mediatek.com> In-Reply-To: <20210804082230.10837-3-Kuan-Ying.Lee@mediatek.com> From: Marco Elver Date: Wed, 4 Aug 2021 10:41:25 +0200 Message-ID: Subject: Re: [PATCH v2 2/2] kasan, slub: reset tag when printing address To: Kuan-Ying Lee Cc: Nicholas Tang , Andrew Yang , Andrey Konovalov , Andrey Ryabinin , Alexander Potapenko , Catalin Marinas , Chinwen Chang , Andrew Morton , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Aug 2021 at 10:23, Kuan-Ying Lee wrote: > > The address still includes the tags when it is printed. > With hardware tag-based kasan enabled, we will get a > false positive KASAN issue when we access metadata. > > Reset the tag before we access the metadata. > > Fixes: aa1ef4d7b3f6 ("kasan, mm: reset tags when accessing metadata") > Signed-off-by: Kuan-Ying Lee > Suggested-by: Marco Elver Note, in this case Suggested-by is inappropriate, because I did not suggest the change in any way (you already had it in v1). I just commented on the fact that it's missing a Fixes so stable can pick it up and some clarification. Reviewed-by: Marco Elver > --- > mm/slub.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > index b6c5205252eb..f77d8cd79ef7 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -576,8 +576,8 @@ static void print_section(char *level, char *text, u8 *addr, > unsigned int length) > { > metadata_access_enable(); > - print_hex_dump(level, kasan_reset_tag(text), DUMP_PREFIX_ADDRESS, > - 16, 1, addr, length, 1); > + print_hex_dump(level, text, DUMP_PREFIX_ADDRESS, > + 16, 1, kasan_reset_tag((void *)addr), length, 1); > metadata_access_disable(); > } > > -- > 2.18.0