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=-23.3 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_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 4ADBFC433E9 for ; Wed, 13 Jan 2021 16:27:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AE1D22339D for ; Wed, 13 Jan 2021 16:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE1D22339D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 175236B015E; Wed, 13 Jan 2021 11:27:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 14BEB6B0160; Wed, 13 Jan 2021 11:27:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 063856B0161; Wed, 13 Jan 2021 11:27:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0243.hostedemail.com [216.40.44.243]) by kanga.kvack.org (Postfix) with ESMTP id E4B436B015E for ; Wed, 13 Jan 2021 11:27:11 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A68A8181AEF10 for ; Wed, 13 Jan 2021 16:27:11 +0000 (UTC) X-FDA: 77701281462.25.tin96_380d1cb2751f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 7CF9E1804DF61 for ; Wed, 13 Jan 2021 16:27:11 +0000 (UTC) X-HE-Tag: tin96_380d1cb2751f X-Filterd-Recvd-Size: 9047 Received: from mail-ot1-f53.google.com (mail-ot1-f53.google.com [209.85.210.53]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Wed, 13 Jan 2021 16:27:10 +0000 (UTC) Received: by mail-ot1-f53.google.com with SMTP id n42so2387509ota.12 for ; Wed, 13 Jan 2021 08:27:10 -0800 (PST) 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=ToZseukMUfS4/Mno4fjs/e3BlupSLArbp20G4eoQPpc=; b=k902rbsbnxoc+Bj5N0U5Acwa809QXnhgEHkNURHH3wpV0km+RTurtwNORXWGgNzMhD oODhyAMjS70nopnlr2Uxp6jRWJaFmu2fj84kolLW2SFhwDlCMky3rqIht5Ea7DBHL2Z0 oVhG7ZDhy+W6GcQujNmDd9BbTbBiKcQurznSA636KA+VdMGOjbTnY0aQAEqYX1AaCgUG sCFy3z6u7aWY09M8BcMvMHovX59JbFjCUCP+sqOQirQCBX1qTJlnJ1Z4xTb4czvxMoE2 R8loMXO6IAkNWPyWwNYdifcUIO//KEIlNpUXHlkvXpozxPoozPLzRZI+fiPClmWYT/Xm ihGg== 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=ToZseukMUfS4/Mno4fjs/e3BlupSLArbp20G4eoQPpc=; b=lDO6Bv7Xwk/HeUMqir6AbtS+emyF2paZKst3Daze1s3JL1OyerG8Vw/m/yuVcn++gd pGvZ6zb1kyl9RTqhpLchtJVfhuoyJoigsMgGCgdGEuNARzbfkq176hggFPDO7jdbEcBg s6lH5p6DF/KYh88Lv8TCaCtrfpertsPrYZUeq+HYHQH8yT6YgFN82ARd4niVCB8ND2bV 99n1AfJDVh6Cg2sjHeQDqfth6+pbvuRrk6xPI+Muqb9kpX2mPfGQ4ljp8OBAaLaeUYCv pdE+2g/o89OrGgoI1uCm1UJHYA920gWK8K/IHBSml6IGXmrEFosmvQ05nLHcx8woUnyG w+qQ== X-Gm-Message-State: AOAM531u7KFxtTRAJHid4RRb5t8zlmgdSehtj2HLpsREskE03/wVN3ZN xTMD4csedHx5iNoB7UJEwr+rA4b4F1mogvy7tQg0Vg== X-Google-Smtp-Source: ABdhPJw0Qd7K/zT8zJ06tvDTzutjwuFCqmusr6CvuuRdVbsyHJZR2KOJ/cChg024Rs9ADuW9aH8veLV6EytfRwXLSao= X-Received: by 2002:a05:6830:2413:: with SMTP id j19mr1826937ots.251.1610555230134; Wed, 13 Jan 2021 08:27:10 -0800 (PST) MIME-Version: 1.0 References: <351f554b6e4c4c0581d15d7b70cbbacf238c887f.1610554432.git.andreyknvl@google.com> In-Reply-To: <351f554b6e4c4c0581d15d7b70cbbacf238c887f.1610554432.git.andreyknvl@google.com> From: Marco Elver Date: Wed, 13 Jan 2021 17:26:58 +0100 Message-ID: Subject: Re: [PATCH v2 05/14] kasan: add match-all tag tests To: Andrey Konovalov Cc: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Andrew Morton , Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev , Linux ARM , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 13 Jan 2021 at 17:21, Andrey Konovalov wrote: > > Add 3 new tests for tag-based KASAN modes: > > 1. Check that match-all pointer tag is not assigned randomly. > 2. Check that 0xff works as a match-all pointer tag. > 3. Check that there are no match-all memory tags. > > Note, that test #3 causes a significant number (255) of KASAN reports > to be printed during execution for the SW_TAGS mode. > > Link: https://linux-review.googlesource.com/id/I78f1375efafa162b37f3abcb2c5bc2f3955dfd8e > Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver > --- > lib/test_kasan.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++ > mm/kasan/kasan.h | 6 ++++ > 2 files changed, 98 insertions(+) > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > index 714ea27fcc3e..f5470bed50b6 100644 > --- a/lib/test_kasan.c > +++ b/lib/test_kasan.c > @@ -13,6 +13,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -754,6 +755,94 @@ static void vmalloc_oob(struct kunit *test) > vfree(area); > } > > +/* > + * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN, > + * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based > + * modes. > + */ > +static void match_all_not_assigned(struct kunit *test) > +{ > + char *ptr; > + struct page *pages; > + int i, size, order; > + > + KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); > + > + for (i = 0; i < 256; i++) { > + size = get_random_int() % 1024; > + ptr = kmalloc(size, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > + KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); > + KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); > + kfree(ptr); > + } > + > + for (i = 0; i < 256; i++) { > + order = get_random_int() % 4; > + pages = alloc_pages(GFP_KERNEL, order); > + ptr = page_address(pages); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > + KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); > + KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); > + free_pages((unsigned long)ptr, order); > + } > +} > + > +/* Check that 0xff works as a match-all pointer tag for tag-based modes. */ > +static void match_all_ptr_tag(struct kunit *test) > +{ > + char *ptr; > + u8 tag; > + > + KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); > + > + ptr = kmalloc(128, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > + > + /* Backup the assigned tag. */ > + tag = get_tag(ptr); > + KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL); > + > + /* Reset the tag to 0xff.*/ > + ptr = set_tag(ptr, KASAN_TAG_KERNEL); > + > + /* This access shouldn't trigger a KASAN report. */ > + *ptr = 0; > + > + /* Recover the pointer tag and free. */ > + ptr = set_tag(ptr, tag); > + kfree(ptr); > +} > + > +/* Check that there are no match-all memory tags for tag-based modes. */ > +static void match_all_mem_tag(struct kunit *test) > +{ > + char *ptr; > + int tag; > + > + KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); > + > + ptr = kmalloc(128, GFP_KERNEL); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > + KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); > + > + /* For each possible tag value not matching the pointer tag. */ > + for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) { > + if (tag == get_tag(ptr)) > + continue; > + > + /* Mark the first memory granule with the chosen memory tag. */ > + kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag); > + > + /* This access must cause a KASAN report. */ > + KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0); > + } > + > + /* Recover the memory tag and free. */ > + kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr)); > + kfree(ptr); > +} > + > static struct kunit_case kasan_kunit_test_cases[] = { > KUNIT_CASE(kmalloc_oob_right), > KUNIT_CASE(kmalloc_oob_left), > @@ -793,6 +882,9 @@ static struct kunit_case kasan_kunit_test_cases[] = { > KUNIT_CASE(kasan_bitops_tags), > KUNIT_CASE(kmalloc_double_kzfree), > KUNIT_CASE(vmalloc_oob), > + KUNIT_CASE(match_all_not_assigned), > + KUNIT_CASE(match_all_ptr_tag), > + KUNIT_CASE(match_all_mem_tag), > {} > }; > > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index 3b38baddec47..c3fb9bf241d3 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -36,6 +36,12 @@ extern bool kasan_flag_panic __ro_after_init; > #define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ > #define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ > > +#ifdef CONFIG_KASAN_HW_TAGS > +#define KASAN_TAG_MIN 0xF0 /* mimimum value for random tags */ > +#else > +#define KASAN_TAG_MIN 0x00 /* mimimum value for random tags */ > +#endif > + > #ifdef CONFIG_KASAN_GENERIC > #define KASAN_FREE_PAGE 0xFF /* page was freed */ > #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ > -- > 2.30.0.284.gd98b1dd5eaa7-goog >