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, USER_AGENT_GIT,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 8E7A8C433DB for ; Fri, 5 Feb 2021 17:40:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4668D60C3F for ; Fri, 5 Feb 2021 17:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229690AbhBEP5h (ORCPT ); Fri, 5 Feb 2021 10:57:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233381AbhBEPxY (ORCPT ); Fri, 5 Feb 2021 10:53:24 -0500 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 51B80C06178B for ; Fri, 5 Feb 2021 09:35:06 -0800 (PST) Received: by mail-wm1-x349.google.com with SMTP id x20so4120392wmc.0 for ; Fri, 05 Feb 2021 09:35:06 -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=WvobzSj421U2nh52f1sEoHIHe/BM9iFVUw3RqQILbkc=; b=NNedEXHnWuo6mudQu55pc85Aj8ZkARgExTe1GyiP//qvZCPgdJYoRMIytaxulPpENP 5m1UVeBdJCEJGndVwvbfCkgSYO0C9rL4pVy43HKK1B1XVeNg5b62xCGqn5v8Qh+IlOCL Z8y1xgKP51VVTVAvtqhaGHX2Gd2rlut623m9JBsMdQ0JCtXKRh0cZUakJeUCSgW01IFW 4jDbbpMJf1turd9ap5dKzKvSp1aSdk/eco4V90CWDmBtbcR0DLoHGPdb6wFqGhfy1ifP bOnqCbXQFu7nWzu5ypuM4z61ktabT+Xr2DOtVjR+7zwFld+Mi9L68l/xjVzO+c81Wm5k ynDA== 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=WvobzSj421U2nh52f1sEoHIHe/BM9iFVUw3RqQILbkc=; b=njiLIKMe7UyWwFADB7anEJRXn6LtAOdMD/HjystIruWBpGMvBCr9Ofpj5wsBL0rzwa AnVBFErvjGCMiXkuyBIADmCuTXlAzXWzP+hW2qOhQ9Ii7NfxZa3K3zGTFJSrEB/jidm3 Qnf51L1/9U2+zsm7I8qdXn6+12CLwGSBJz8/rJStfTkiQg6r51EJgZZfr5lYhMf+fpsF IIAE0hUmR/ZM3zhZSp+6V5c+hAx7umh9XkSarJ71/iJc4+QwevVUUd4LixPIf4JjPy62 4aU3zFA7qQHYMATURGp/1vXolod//wo4vOJ2QPsSEvr4U/YMwqKufPk6asmZeFEhnHqx X5Nw== X-Gm-Message-State: AOAM533BHDIcUitmRQ/Dgc6yMt4EF+o5MZgnc2+voXnWSG1kvR4fK72a 70/o0M5bOOksy552RCqzEHYdrUXMqfhnF7p7 X-Google-Smtp-Source: ABdhPJx4HJoO7CbKgZftXFbdt22PtMMn75VuP2ft+tzw4fvt8SPfqelmj8N1SzNcHwszBmgAjB1HSrpNRQNyRInI Sender: "andreyknvl via sendgmr" X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:edb8:b79c:2e20:e531]) (user=andreyknvl job=sendgmr) by 2002:a05:600c:154f:: with SMTP id f15mr4396184wmg.20.1612546504994; Fri, 05 Feb 2021 09:35:04 -0800 (PST) Date: Fri, 5 Feb 2021 18:34:40 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v3 mm 06/13] kasan: rework krealloc tests 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 This patch reworks KASAN-KUnit tests for krealloc() to: 1. Check both slab and page_alloc based krealloc() implementations. 2. Allow at least one full granule to fit between old and new sizes for each KASAN mode, and check accesses to that granule accordingly. Reviewed-by: Marco Elver Signed-off-by: Andrey Konovalov --- lib/test_kasan.c | 91 ++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 81 insertions(+), 10 deletions(-) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index d16ec9e66806..ffebad2f0e6e 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -252,11 +252,14 @@ static void kmalloc_large_oob_right(struct kunit *test) kfree(ptr); } -static void kmalloc_oob_krealloc_more(struct kunit *test) +static void krealloc_more_oob_helper(struct kunit *test, + size_t size1, size_t size2) { char *ptr1, *ptr2; - size_t size1 = 17; - size_t size2 = 19; + size_t middle; + + KUNIT_ASSERT_LT(test, size1, size2); + middle = size1 + (size2 - size1) / 2; ptr1 = kmalloc(size1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); @@ -264,15 +267,31 @@ static void kmalloc_oob_krealloc_more(struct kunit *test) ptr2 = krealloc(ptr1, size2, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); - KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x'); + /* All offsets up to size2 must be accessible. */ + ptr2[size1 - 1] = 'x'; + ptr2[size1] = 'x'; + ptr2[middle] = 'x'; + ptr2[size2 - 1] = 'x'; + + /* Generic mode is precise, so unaligned size2 must be inaccessible. */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x'); + + /* For all modes first aligned offset after size2 must be inaccessible. */ + KUNIT_EXPECT_KASAN_FAIL(test, + ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x'); + kfree(ptr2); } -static void kmalloc_oob_krealloc_less(struct kunit *test) +static void krealloc_less_oob_helper(struct kunit *test, + size_t size1, size_t size2) { char *ptr1, *ptr2; - size_t size1 = 17; - size_t size2 = 15; + size_t middle; + + KUNIT_ASSERT_LT(test, size2, size1); + middle = size2 + (size1 - size2) / 2; ptr1 = kmalloc(size1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); @@ -280,10 +299,60 @@ static void kmalloc_oob_krealloc_less(struct kunit *test) ptr2 = krealloc(ptr1, size2, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); - KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x'); + /* Must be accessible for all modes. */ + ptr2[size2 - 1] = 'x'; + + /* Generic mode is precise, so unaligned size2 must be inaccessible. */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x'); + + /* For all modes first aligned offset after size2 must be inaccessible. */ + KUNIT_EXPECT_KASAN_FAIL(test, + ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x'); + + /* + * For all modes all size2, middle, and size1 should land in separate + * granules and thus the latter two offsets should be inaccessible. + */ + KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE), + round_down(middle, KASAN_GRANULE_SIZE)); + KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE), + round_down(size1, KASAN_GRANULE_SIZE)); + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x'); + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x'); + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x'); + kfree(ptr2); } +static void krealloc_more_oob(struct kunit *test) +{ + krealloc_more_oob_helper(test, 201, 235); +} + +static void krealloc_less_oob(struct kunit *test) +{ + krealloc_less_oob_helper(test, 235, 201); +} + +static void krealloc_pagealloc_more_oob(struct kunit *test) +{ + /* page_alloc fallback in only implemented for SLUB. */ + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB); + + krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201, + KMALLOC_MAX_CACHE_SIZE + 235); +} + +static void krealloc_pagealloc_less_oob(struct kunit *test) +{ + /* page_alloc fallback in only implemented for SLUB. */ + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB); + + krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235, + KMALLOC_MAX_CACHE_SIZE + 201); +} + static void kmalloc_oob_16(struct kunit *test) { struct { @@ -977,8 +1046,10 @@ static struct kunit_case kasan_kunit_test_cases[] = { KUNIT_CASE(pagealloc_oob_right), KUNIT_CASE(pagealloc_uaf), KUNIT_CASE(kmalloc_large_oob_right), - KUNIT_CASE(kmalloc_oob_krealloc_more), - KUNIT_CASE(kmalloc_oob_krealloc_less), + KUNIT_CASE(krealloc_more_oob), + KUNIT_CASE(krealloc_less_oob), + KUNIT_CASE(krealloc_pagealloc_more_oob), + KUNIT_CASE(krealloc_pagealloc_less_oob), KUNIT_CASE(kmalloc_oob_16), KUNIT_CASE(kmalloc_uaf_16), KUNIT_CASE(kmalloc_oob_in_memset), -- 2.30.0.365.g02bc693789-goog