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=-18.1 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 127BDC4727E for ; Wed, 30 Sep 2020 12:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C3DB920719 for ; Wed, 30 Sep 2020 12:51:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="L7X6TOpx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730025AbgI3MvN (ORCPT ); Wed, 30 Sep 2020 08:51:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725776AbgI3MvM (ORCPT ); Wed, 30 Sep 2020 08:51:12 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74D2DC061755 for ; Wed, 30 Sep 2020 05:51:12 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id x23so1578706wmi.3 for ; Wed, 30 Sep 2020 05:51:12 -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:content-transfer-encoding; bh=061+j+6egSPgQBxcQTsTW5phFlVIKpu1EERfRNYFm3I=; b=L7X6TOpxVSA1+/tKoz+lBrre35i6hykvaIsiSKRHazC1OEzRn8KvgpXAhkiiZiVegY hdXFas3bd8RElezjRN1Xeo7xyo7N2TkVLXtqU3NGt5Q8cVO3mr5kv+TEr1CYFZCRj4Z/ NW5e/35SOVX/7oaogpcsuZY+pT2bwreoZd2XwBqQnwrCKrSePcNpSqJb0uFF/Id6AfFs KOYk8XjmATWuR/1g8kLMRJOhm10DPe9hbErIsERzBQXL30eRmJc/Lg9yUE0wgl2QU6er RnRvuI5XvMS9yKOd/4XI7PcEwBEw2l3rf/ujZ4+IWPrfSKuDeZm1cQ/nKtWd1HwBDjMP EdIA== 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:content-transfer-encoding; bh=061+j+6egSPgQBxcQTsTW5phFlVIKpu1EERfRNYFm3I=; b=JC6Py8QXWfg3CHBWQiGHrPMMEauriTfXDEpilfw9LvMC4iLvV09ikv51nPZXuPL4iV PQCjQ1/exU185Jj3QGZdUe9c2aHRW8cv1Xt6ejVbQ862i95Tj3+7vkByDiwqyxwuVvMe /Rdd0Va8o7N3/JVlmO3bDRHvDhLBBYD1b/fuJz8s4TUYoWoiQlpFX5JN//zcgav4+Jki C4Y9ddHaSce4xKyEKB0PecPQwW/75hawLDR4JUf6srqZl6h+Lzu9JGNJRzg1p+PlJBPO e4Pxizw5KdYz1KrrYNVaDt+FK/q07oKfm/WJ/Om7cmgSxJxmn1Bt5Jebx9mfjZ+YwLsq blQw== X-Gm-Message-State: AOAM530RiIw/al0ZrTGvla+iqI6tDG9vhMeDF1VAX3Qm/R+li5COX1ax 1z+OBXBtwyHz1JeNT1rq6zMw8n8+hSEm3pm/ScUqjQ== X-Google-Smtp-Source: ABdhPJzmy6011bRCaz/kYoxOSxfcZV6R3wEOIH1+eORfD6559vOkDZuINzOB4rqg9WTL3BgoD4kKzA3W5h9iSh2kySo= X-Received: by 2002:a7b:cd93:: with SMTP id y19mr2785473wmj.112.1601470270876; Wed, 30 Sep 2020 05:51:10 -0700 (PDT) MIME-Version: 1.0 References: <20200929183513.380760-1-alex.popov@linux.com> <20200929183513.380760-3-alex.popov@linux.com> In-Reply-To: <20200929183513.380760-3-alex.popov@linux.com> From: Alexander Potapenko Date: Wed, 30 Sep 2020 14:50:59 +0200 Message-ID: Subject: Re: [PATCH RFC v2 2/6] mm/slab: Perform init_on_free earlier To: Alexander Popov Cc: Kees Cook , Jann Horn , Will Deacon , Andrey Ryabinin , Dmitry Vyukov , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Masahiro Yamada , Masami Hiramatsu , Steven Rostedt , Peter Zijlstra , Krzysztof Kozlowski , Patrick Bellasi , David Howells , Eric Biederman , Johannes Weiner , Laura Abbott , Arnd Bergmann , Greg Kroah-Hartman , Daniel Micay , Andrey Konovalov , Matthew Wilcox , Pavel Machek , Valentin Schneider , kasan-dev , Linux Memory Management List , Kernel Hardening , LKML , notify@kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 29, 2020 at 8:35 PM Alexander Popov wrot= e: > > Currently in CONFIG_SLAB init_on_free happens too late, and heap > objects go to the heap quarantine being dirty. Lets move memory > clearing before calling kasan_slab_free() to fix that. > > Signed-off-by: Alexander Popov Reviewed-by: Alexander Potapenko > --- > mm/slab.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 3160dff6fd76..5140203c5b76 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3414,6 +3414,9 @@ static void cache_flusharray(struct kmem_cache *cac= hep, struct array_cache *ac) > static __always_inline void __cache_free(struct kmem_cache *cachep, void= *objp, > unsigned long caller) > { > + if (unlikely(slab_want_init_on_free(cachep))) > + memset(objp, 0, cachep->object_size); > + > /* Put the object into the quarantine, don't touch it for now. */ > if (kasan_slab_free(cachep, objp, _RET_IP_)) > return; > @@ -3432,8 +3435,6 @@ void ___cache_free(struct kmem_cache *cachep, void = *objp, > struct array_cache *ac =3D cpu_cache_get(cachep); > > check_irq_off(); > - if (unlikely(slab_want_init_on_free(cachep))) > - memset(objp, 0, cachep->object_size); > kmemleak_free_recursive(objp, cachep->flags); > objp =3D cache_free_debugcheck(cachep, objp, caller); > memcg_slab_free_hook(cachep, virt_to_head_page(objp), objp); > -- > 2.26.2 > --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg