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=-12.6 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 77659C433E2 for ; Mon, 7 Sep 2020 13:46:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EC8920757 for ; Mon, 7 Sep 2020 13:46:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="W3a/pmyA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729603AbgIGNpZ (ORCPT ); Mon, 7 Sep 2020 09:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729565AbgIGNoH (ORCPT ); Mon, 7 Sep 2020 09:44:07 -0400 Received: from mail-wm1-x349.google.com (mail-wm1-x349.google.com [IPv6:2a00:1450:4864:20::349]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46175C06179E for ; Mon, 7 Sep 2020 06:41:28 -0700 (PDT) Received: by mail-wm1-x349.google.com with SMTP id m25so3995119wmi.0 for ; Mon, 07 Sep 2020 06:41:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=sBEgph2pOr6CyODJ1uv8I0m4yR8SDTujVHr8yLlCuyo=; b=W3a/pmyA4RP9Ik4+QJ2hBf7+DdC59fjkdllmpsJW+SIiBQPN3kXyd9Kl+hHv33LAO8 0Rl7721pKfQjoHvZg5qD3ApYcG4ud82WNSxk7OFQ5p/DRxsI/wc1hgGYCDwxpDPlrMau 1vD8JshMZ5eXQ4eGdi+NX6QBfAAU1zXfaEEcd+/iPcOipwfLCv04EDrJPjCN2JfNQS2n hWtjfI6XY4eAGv7F9YdcWmMVOGPddTqLNehEiIxh84gokds7aOpJU/34ej4ZdtXwGqGd r7/F6AXB3t228e8XH01xJURnu3n83x2f94oZoI5f1Dg+cwUdzI69z9A1ttcD+jnYVWPP 2ryQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=sBEgph2pOr6CyODJ1uv8I0m4yR8SDTujVHr8yLlCuyo=; b=HtiliA1/sgLasxdf1WxlVPTJnvH8763bQFIt3y5Nm6QhTEbMW0iL8F1yV2RzxpVVp+ /+OtOeYdeXujhXFhY1q8d00Nrstm6pcPrv5T1fLdp/thNxOiQAUjB0cULwHxRvVrWqGX OmaHfhbfv8s9tCMM4P9cgEWl/UJzwmKD1+lKPr1iZDeSiYpNVh7F6bA4fH6od1sl1Y/I kWfH+gGR3JbzEHVsVtsKVv+8/MtkHuH9pjd6YU8N8o/yYHJSwkBskhVHV2ZhOzKwOGnY /xkDQ12iEyN9ceRsgTfomUSd93M7vfryMu6KUtixev18I4+d9d6hLzMGKtTxSihWI22l dTVg== X-Gm-Message-State: AOAM533tm8mc68pND3vtLr0X9lHqOuXFhAKp+FdgiOKD8ssAVK4o6n0P jPbnXADIZywUyuqXxuq6WHaY5dxAlA== X-Google-Smtp-Source: ABdhPJxeJUaJi1Li1DPHii5Sj4LSLAplbFw0CU8QzsUMSMD+wpw59PJfS96CMu44VRwFFVbpHpJk5iEgwg== X-Received: from elver.muc.corp.google.com ([2a00:79e0:15:13:f693:9fff:fef4:2449]) (user=elver job=sendgmr) by 2002:a7b:c019:: with SMTP id c25mr9339wmb.0.1599486083942; Mon, 07 Sep 2020 06:41:23 -0700 (PDT) Date: Mon, 7 Sep 2020 15:40:51 +0200 In-Reply-To: <20200907134055.2878499-1-elver@google.com> Message-Id: <20200907134055.2878499-7-elver@google.com> Mime-Version: 1.0 References: <20200907134055.2878499-1-elver@google.com> X-Mailer: git-send-email 2.28.0.526.ge36021eeef-goog Subject: [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN From: Marco Elver To: elver@google.com, glider@google.com, akpm@linux-foundation.org, catalin.marinas@arm.com, cl@linux.com, rientjes@google.com, iamjoonsoo.kim@lge.com, mark.rutland@arm.com, penberg@kernel.org Cc: hpa@zytor.com, paulmck@kernel.org, andreyknvl@google.com, aryabinin@virtuozzo.com, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, dvyukov@google.com, edumazet@google.com, gregkh@linuxfoundation.org, mingo@redhat.com, jannh@google.com, corbet@lwn.net, keescook@chromium.org, peterz@infradead.org, cai@lca.pw, tglx@linutronix.de, will@kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Alexander Potapenko We make KFENCE compatible with KASAN for testing KFENCE itself. In particular, KASAN helps to catch any potential corruptions to KFENCE state, or other corruptions that may be a result of freepointer corruptions in the main allocators. To indicate that the combination of the two is generally discouraged, CONFIG_EXPERT=y should be set. It also gives us the nice property that KFENCE will be build-tested by allyesconfig builds. Co-developed-by: Marco Elver Signed-off-by: Marco Elver Signed-off-by: Alexander Potapenko --- lib/Kconfig.kfence | 2 +- mm/kasan/common.c | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence index 7ac91162edb0..b080e49e15d4 100644 --- a/lib/Kconfig.kfence +++ b/lib/Kconfig.kfence @@ -10,7 +10,7 @@ config HAVE_ARCH_KFENCE_STATIC_POOL menuconfig KFENCE bool "KFENCE: low-overhead sampling-based memory safety error detector" - depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB) + depends on HAVE_ARCH_KFENCE && (!KASAN || EXPERT) && (SLAB || SLUB) depends on JUMP_LABEL # To ensure performance, require jump labels select STACKTRACE help diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 950fd372a07e..f5c49f0fdeff 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -396,6 +397,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object, tagged_object = object; object = reset_tag(object); + if (is_kfence_address(object)) + return false; + if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) != object)) { kasan_report_invalid_free(tagged_object, ip); @@ -444,6 +448,9 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, if (unlikely(object == NULL)) return NULL; + if (is_kfence_address(object)) + return (void *)object; + redzone_start = round_up((unsigned long)(object + size), KASAN_SHADOW_SCALE_SIZE); redzone_end = round_up((unsigned long)object + cache->object_size, -- 2.28.0.526.ge36021eeef-goog