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=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 204F5C43381 for ; Wed, 13 Mar 2019 19:18:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7D152171F for ; Wed, 13 Mar 2019 19:18:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="NcmTjTnP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729091AbfCMTSi (ORCPT ); Wed, 13 Mar 2019 15:18:38 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:33467 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728568AbfCMTSh (ORCPT ); Wed, 13 Mar 2019 15:18:37 -0400 Received: by mail-pg1-f195.google.com with SMTP id h11so2229296pgl.0 for ; Wed, 13 Mar 2019 12:18:36 -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=FWhPJ3WNEGAzoi65eJxiwmXgvhDwWzZG2Rd8Px4UT/M=; b=NcmTjTnP669KpQSaJDsEVbwa7ZSzy7RTfIIe13UmBh3jYlwMYcna5tYe4UPD7K0QWp FIrtHvkbkTM8ZBWJ3XThzGI16NdwnR8y7gi2UQUoklv18NqvNlv4dUVkMLbgqH27ruof dMtQcwagO8GS1fAZKEB8X4sTCzzPxWzs+1gOQVLVU38G4SmKQ1h6nrViaEOFgwalljeG 55Bjh7XKlWG2CJ+yxYisD8n8CKG6RRXlonBc96iYd7oScLW/Vq1waoOB7NOdC6jSE6/W zzdnOCFfi4SnFgQd4EK3xcv0kGMPk3W5KRAEg09Ml/WZwYTy1iA0HnD/paLeGOZvXgsF GzRA== 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=FWhPJ3WNEGAzoi65eJxiwmXgvhDwWzZG2Rd8Px4UT/M=; b=erQ6qLpGMS+f5sfjDpGz5JfGl2JKQ0u8U3DaW2BOuFKlyPcvzHKhawg3mboVY1DLU8 /UvFOnK/MVd74vZGms5drNEF854kg2uWieTEAFeAyHrzcPg00couOHjLHUuiHnh8/yRe 7Ft6aLNzvifmufAMX8nZTTWuuXDExau+5kSvunYRD4zMtZW+skp5S4SNWuHtieb7fzBy mmYr+RYX6/iHRwtUl+C6kGQdirylZfzbq5WdJ/bR0LC6t8tXThKZypvHYUttsfI+KZud QZHdxnMnC/+oWBBy+27XyEM11CAdbghV7XjRxhYzmRrTzeeofLPLO3ebHsYFkSbuseJX IJ1Q== X-Gm-Message-State: APjAAAUtJphkuXmtVfT5Bb6qMnKrqxdudrvxy/PlfYJG6lrLYFxbD7/k ao4UbKq6jOR6z83A/siVio96+qoQYQBcrFHl0Vm/eXbx X-Google-Smtp-Source: APXvYqyhqJNYym2YNvO7ZRCVAOdtXq1+cu5eY/wmttmIdLIRskcfobIWUY0/oQcJh6Qub3CfDQ7R1ZoFLvgFmhtTDG0= X-Received: by 2002:a65:6651:: with SMTP id z17mr39579463pgv.95.1552504715765; Wed, 13 Mar 2019 12:18:35 -0700 (PDT) MIME-Version: 1.0 References: <20190313191506.159677-1-sashal@kernel.org> <20190313191506.159677-22-sashal@kernel.org> In-Reply-To: <20190313191506.159677-22-sashal@kernel.org> From: Andrey Konovalov Date: Wed, 13 Mar 2019 20:18:24 +0100 Message-ID: Subject: Re: [PATCH AUTOSEL 4.14 22/33] kasan, slab: make freelist stored without tags To: Sasha Levin Cc: LKML , stable , Alexander Potapenko , Andrey Ryabinin , Catalin Marinas , Dmitry Vyukov , Evgeniy Stepanov , Kostya Serebryany , Vincenzo Frascino , Andrew Morton , Linus Torvalds , Linux Memory Management List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 13, 2019 at 8:16 PM Sasha Levin wrote: > > From: Andrey Konovalov > > [ Upstream commit 51dedad06b5f6c3eea7ec1069631b1ef7796912a ] Hi Sasha, None of the 4.9, 4.14, 4.19 or 4.20 have tag-based KASAN, so backporting these 3 KASAN related patches doesn't make much sense. Thanks! > > Similarly to "kasan, slub: move kasan_poison_slab hook before > page_address", move kasan_poison_slab() before alloc_slabmgmt(), which > calls page_address(), to make page_address() return value to be > non-tagged. This, combined with calling kasan_reset_tag() for off-slab > slab management object, leads to freelist being stored non-tagged. > > Link: http://lkml.kernel.org/r/dfb53b44a4d00de3879a05a9f04c1f55e584f7a1.1550602886.git.andreyknvl@google.com > Signed-off-by: Andrey Konovalov > Tested-by: Qian Cai > Cc: Alexander Potapenko > Cc: Andrey Ryabinin > Cc: Catalin Marinas > Cc: Dmitry Vyukov > Cc: Evgeniy Stepanov > Cc: Kostya Serebryany > Cc: Vincenzo Frascino > Signed-off-by: Andrew Morton > Signed-off-by: Linus Torvalds > Signed-off-by: Sasha Levin > --- > mm/slab.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/mm/slab.c b/mm/slab.c > index 409631e49295..766043dd3f8e 100644 > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -2378,6 +2378,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep, > /* Slab management obj is off-slab. */ > freelist = kmem_cache_alloc_node(cachep->freelist_cache, > local_flags, nodeid); > + freelist = kasan_reset_tag(freelist); > if (!freelist) > return NULL; > } else { > @@ -2690,6 +2691,13 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep, > > offset *= cachep->colour_off; > > + /* > + * Call kasan_poison_slab() before calling alloc_slabmgmt(), so > + * page_address() in the latter returns a non-tagged pointer, > + * as it should be for slab pages. > + */ > + kasan_poison_slab(page); > + > /* Get slab management. */ > freelist = alloc_slabmgmt(cachep, page, offset, > local_flags & ~GFP_CONSTRAINT_MASK, page_node); > @@ -2698,7 +2706,6 @@ static struct page *cache_grow_begin(struct kmem_cache *cachep, > > slab_map_pages(cachep, page, freelist); > > - kasan_poison_slab(page); > cache_init_objs(cachep, page); > > if (gfpflags_allow_blocking(local_flags)) > -- > 2.19.1 >