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=-26.3 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_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 4D4B9C433E9 for ; Fri, 15 Jan 2021 17:55:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CD0C23A5A for ; Fri, 15 Jan 2021 17:55:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387597AbhAORys (ORCPT ); Fri, 15 Jan 2021 12:54:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733061AbhAORyX (ORCPT ); Fri, 15 Jan 2021 12:54:23 -0500 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C560AC06179B for ; Fri, 15 Jan 2021 09:53:22 -0800 (PST) Received: by mail-qt1-x849.google.com with SMTP id d26so1489605qto.7 for ; Fri, 15 Jan 2021 09:53:22 -0800 (PST) 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=BYOOBCCudRU7Lchp5NpxZrw19s2hqbj4Q5eYKa3nns4=; b=oOLTb6iXGw4hR7fdl1kwHC5xGAza1F2tagz3FB0QzJWJZ+QDQztqyFMI5YtXoJnkKe Y8bnNIHQQI6h6YZB8c5JWJITMJwTcCVPccnXBUAH6v53fuzil8/YZQvPlWRIfbIJkX3k QhAZskFpCa+ydA7ejU09Rldhgnq+lomoiasoPI+wLLennUluX7zlgEMOvZlu3aSu/uya REciLVBKZ8HB9mefgBiy1+ygnJg5QEKOGO6TqXqwlYLg9xnZFQb6ydAdwrbnQTcVow6C lv0wjw4582nq09tW4GEKePRBzsLb1hpFJGbAuym5d3D1p8/Qq+uq1wl9ctzgSvCa1YwV Mf6Q== 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=BYOOBCCudRU7Lchp5NpxZrw19s2hqbj4Q5eYKa3nns4=; b=f3PJD5u93Q6zKwnTWH8d5beMkWCl60SUpF77dqdAXDTcreeyxXDXm+xIsyjVwOswvM XdAzhyTNuvBMzDTJgLwroi73LAIwH4ORzt3M/RNQt/oTC+uTn3Hnd5Ygil9UxVWeBMDX uAK2AfYoQyWCCCZqaP0HXZsx26+dHviDoxz3DkP1ZWUtxhRAOP93sb1veYMNggAqOvSB pLDNBhCAj9TZs7DvAxyPAYpbHSb/Rkvj0f3uhAEMOLipzReZIr3I+Y0G7XuWUPwh/S+L 6WNh47/a46ZViLLPKnSbHmrJOF5FlxNJXhgIYOplKAACzOhMl+qnhCilDSpT900qzHPU L3Fw== X-Gm-Message-State: AOAM5326OYmvoWIZ838aUbfTmRaBI6no+lNP4no3QX3tGVJH3kYkNf3t BTiN76zCcj4GBmkFwE41YzkuxzaN5cUknnH4 X-Google-Smtp-Source: ABdhPJzKh8C6qw7cdRynOQL3HqGoll2W7wn9Iq+M7R+ck7opki/cSqyWyZcMuFOd2GLp4ocvgj4w963nEuh9ZJCs Sender: "andreyknvl via sendgmr" X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:ad4:5188:: with SMTP id b8mr13230051qvp.55.1610733201718; Fri, 15 Jan 2021 09:53:21 -0800 (PST) Date: Fri, 15 Jan 2021 18:52:46 +0100 In-Reply-To: Message-Id: <9cd5cf2f633dcbf55cab801cd26845d2b075cec7.1610733117.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH v4 09/15] kasan: adapt kmalloc_uaf2 test to HW_TAGS mode From: Andrey Konovalov To: Andrew Morton , Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Marco Elver Cc: Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the kmalloc_uaf2() test, the pointers to the two allocated memory blocks might happen to be the same, and the test will fail. With the software tag-based mode, the probability of the that is 1/254, so it's hard to observe the failure. For the hardware tag-based mode though, the probablity is 1/14, which is quite noticable. Allow up to 16 attempts at generating different tags for the tag-based modes. Link: https://linux-review.googlesource.com/id/Ibfa458ef2804ff465d8eb07434a300bf36388d55 Reviewed-by: Marco Elver Reviewed-by: Alexander Potapenko Signed-off-by: Andrey Konovalov --- lib/test_kasan.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 2419e36e117b..0cda4a1ff394 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -382,7 +382,9 @@ static void kmalloc_uaf2(struct kunit *test) { char *ptr1, *ptr2; size_t size = 43; + int counter = 0; +again: ptr1 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); @@ -391,6 +393,15 @@ static void kmalloc_uaf2(struct kunit *test) ptr2 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); + /* + * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same. + * Allow up to 16 attempts at generating different tags. + */ + if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) { + kfree(ptr2); + goto again; + } + KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x'); KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2); -- 2.30.0.284.gd98b1dd5eaa7-goog