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=-16.7 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_AGENT_GIT, 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 A2C72C32789 for ; Tue, 6 Nov 2018 17:32:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 641A92085B for ; Tue, 6 Nov 2018 17:32:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="loc8gPpA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 641A92085B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389983AbeKGC6l (ORCPT ); Tue, 6 Nov 2018 21:58:41 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:40555 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389742AbeKGC5P (ORCPT ); Tue, 6 Nov 2018 21:57:15 -0500 Received: by mail-wm1-f68.google.com with SMTP id b203-v6so12992852wme.5 for ; Tue, 06 Nov 2018 09:30:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=T48YNHXSNi4eeu2bzn4PMsbpUkqEeLL24cz/k9DQXN4=; b=loc8gPpA6BsyBfsLQZ1xJJK8SKgPFvND8p3yzI24gRT2R2tnyR8tmqImgBFESqB8u6 PsKYO6u6js23G9tUx/zXdhJPXl+StChQkny+zenERtzcQKXZX8ErExSxCBBX0yJgxY9q ixayJsgrtswgOvbM6wpAqylRzFKJAPeUvLDsu3CzamxYGtDIKdwUQIQqlWUq2a9OtTnM YJ3/ly3iHAfyh/CxczjrHcrrDPYqCFrsso3DtMOk5fQuf3lw29WfInkABtCJROdU18/4 tb44qp9/xEdYSkh/b4qqUwewkJgv1o4YKZIPZTgkYWer1OOoqUZO6eD68PC/TJpFaWzl /5Zg== 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=T48YNHXSNi4eeu2bzn4PMsbpUkqEeLL24cz/k9DQXN4=; b=awG10x+bk2On9/bjQLQwjmQnKympO4lhx8K2Muw7ulJzCwGAsJqsU/RURLUihQJLts 0exVDP06wvWC91KxTSBUATilrOcb9xFc07WOJYLaScLaxPShxNXASKQ+pKblzuaddpYs HTAlbH5/UQC9c2hLxilBFEV5rPXHbUlBLh+aCtLG1R4EPi99PVYRWnd397fKODrzS3lX 2y5/nOmTp0Si7YmM/NpcDrpResOe+LPVaAQov8hP7v+BbpkDj/uQCIs3rnBL1agy9jIZ jv179CyLHHc++1b8MOR7dVnFa0qr+qrFBM2mUV/RMef/bHmc7XLRcz468OeL9fDXAhhn CmYw== X-Gm-Message-State: AGRZ1gKGRPCyDDVgtPUPhxKgTntWf1fRwGIAxIL1bZ8TRlxpw8qyoiLP IGOFxE13HroyzGFKFhgmilvIBQ== X-Google-Smtp-Source: AJdET5cxhc/meAOXt3ESBWUaU6vT9ON5JhSvHyq74Qc/JQ1ollGs24FteiQAUYp/Kw4/4V5LhOwRHw== X-Received: by 2002:a1c:d78e:: with SMTP id o136-v6mr2759533wmg.124.1541525458005; Tue, 06 Nov 2018 09:30:58 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id z17-v6sm16328416wrm.65.2018.11.06.09.30.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Nov 2018 09:30:57 -0800 (PST) From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan , Andrey Konovalov Subject: [PATCH v10 10/22] kasan: preassign tags to objects with ctors or SLAB_TYPESAFE_BY_RCU Date: Tue, 6 Nov 2018 18:30:25 +0100 Message-Id: X-Mailer: git-send-email 2.19.1.930.g4563a0d9d0-goog In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An object constructor can initialize pointers within this objects based on the address of the object. Since the object address might be tagged, we need to assign a tag before calling constructor. The implemented approach is to assign tags to objects with constructors when a slab is allocated and call constructors once as usual. The downside is that such object would always have the same tag when it is reallocated, so we won't catch use-after-frees on it. Also pressign tags for objects from SLAB_TYPESAFE_BY_RCU caches, since they can be validy accessed after having been freed. Reviewed-by: Andrey Ryabinin Reviewed-by: Dmitry Vyukov Signed-off-by: Andrey Konovalov --- mm/slab.c | 2 +- mm/slub.c | 24 ++++++++++++++---------- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 26f60a22e5e0..27859fb39889 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2574,7 +2574,7 @@ static void cache_init_objs(struct kmem_cache *cachep, for (i = 0; i < cachep->num; i++) { objp = index_to_obj(cachep, page, i); - kasan_init_slab_obj(cachep, objp); + objp = kasan_init_slab_obj(cachep, objp); /* constructor could break poison info */ if (DEBUG == 0 && cachep->ctor) { diff --git a/mm/slub.c b/mm/slub.c index e739d46600b9..08740c3f3745 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1451,16 +1451,17 @@ static inline bool slab_free_freelist_hook(struct kmem_cache *s, #endif } -static void setup_object(struct kmem_cache *s, struct page *page, +static void *setup_object(struct kmem_cache *s, struct page *page, void *object) { setup_object_debug(s, page, object); - kasan_init_slab_obj(s, object); + object = kasan_init_slab_obj(s, object); if (unlikely(s->ctor)) { kasan_unpoison_object_data(s, object); s->ctor(object); kasan_poison_object_data(s, object); } + return object; } /* @@ -1568,16 +1569,16 @@ static bool shuffle_freelist(struct kmem_cache *s, struct page *page) /* First entry is used as the base of the freelist */ cur = next_freelist_entry(s, page, &pos, start, page_limit, freelist_count); + cur = setup_object(s, page, cur); page->freelist = cur; for (idx = 1; idx < page->objects; idx++) { - setup_object(s, page, cur); next = next_freelist_entry(s, page, &pos, start, page_limit, freelist_count); + next = setup_object(s, page, next); set_freepointer(s, cur, next); cur = next; } - setup_object(s, page, cur); set_freepointer(s, cur, NULL); return true; @@ -1599,7 +1600,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) struct page *page; struct kmem_cache_order_objects oo = s->oo; gfp_t alloc_gfp; - void *start, *p; + void *start, *p, *next; int idx, order; bool shuffle; @@ -1651,13 +1652,16 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) if (!shuffle) { for_each_object_idx(p, idx, s, start, page->objects) { - setup_object(s, page, p); - if (likely(idx < page->objects)) - set_freepointer(s, p, p + s->size); - else + if (likely(idx < page->objects)) { + next = p + s->size; + next = setup_object(s, page, next); + set_freepointer(s, p, next); + } else set_freepointer(s, p, NULL); } - page->freelist = fixup_red_left(s, start); + start = fixup_red_left(s, start); + start = setup_object(s, page, start); + page->freelist = start; } page->inuse = page->objects; -- 2.19.1.930.g4563a0d9d0-goog