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 B4EE7C433DB for ; Tue, 12 Jan 2021 18:11:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0836822DFA for ; Tue, 12 Jan 2021 18:11:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0836822DFA 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 693A86B0092; Tue, 12 Jan 2021 13:11:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 644F56B0093; Tue, 12 Jan 2021 13:11:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 50CC46B0095; Tue, 12 Jan 2021 13:11:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0220.hostedemail.com [216.40.44.220]) by kanga.kvack.org (Postfix) with ESMTP id 3B4D46B0092 for ; Tue, 12 Jan 2021 13:11:24 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id F1E351EE6 for ; Tue, 12 Jan 2021 18:11:23 +0000 (UTC) X-FDA: 77697915246.03.water03_590352b27517 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id C369F28A240 for ; Tue, 12 Jan 2021 18:11:23 +0000 (UTC) X-HE-Tag: water03_590352b27517 X-Filterd-Recvd-Size: 9185 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Tue, 12 Jan 2021 18:11:23 +0000 (UTC) Received: by mail-pl1-f182.google.com with SMTP id be12so1836027plb.4 for ; Tue, 12 Jan 2021 10:11:23 -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=KHIuhecZMVyLx+ijiJ0VpXni4YAkn1lcKgd4j/76ieY=; b=k2Vk8XGGSMMmBHOZkQLIepIkeJh9g/D70p+FHo+OHkfPbacQXAS+kNhV+TcvtwgXXd PM+RAmMzbz1oe/87tSXng5aOoHrrki42p+cBRISOY3VXssTYJmj07k3fnuhfrW31R9h4 7MY2/JbOSeYBtt/UTJkQnClF1JOM1KHWzi1u5+62w7HV2jap/gv17wJx5T1w66Tpy1Nj 07wPdf71lUGorXIGIbJvkBD9yVdSsd8Dkps9kSZYGxa+0CBCdaQmVRCb6fnYYg0nHnHE J2NQRCbz3pQg7RjrNlr5l5FDhnHkaJaCtzzv587CXvAS5hN+SoxsJXVbiZkdjnw1Qd6o H9hQ== 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=KHIuhecZMVyLx+ijiJ0VpXni4YAkn1lcKgd4j/76ieY=; b=hzHmNBY8+ZTjyvUXogykA7AxorYhsc2FEoOZDwS077Lr0sJqhRB+ZEmONNCuYZA0fT Oo1KJibeMWblRLSX992yZEQQod6mvqZLPd841otVRn/qMn8/Mpa9ktEWyot46UZvbfx5 8nuxat97koYwKoo15EOvaiBR8xcu38kR474Hn/jUxwgBg68ogyWqQPfYq/StwmfdpJb2 O3kBNU8CzXglDkPUtk9T+8ZwbnvVy41dtG4iHzs46TimFB1LtAPCzdZaLxe7rY7Uv48D s5tG57IWvmh/DGxK0jEO/u6wcKyRzNnDBhWeFYUxSGwNVKv6Xas3GsjM1LBzNpdEYS2J OUzA== X-Gm-Message-State: AOAM530uBqlwWHQ3nC1/j1NZe6Lll8wsvJj0xr4EMZBUz+qs6/tif2Ch cexUnzAGjHcjmaykoSrdyCs1GxZmzAMgQNSou5X45w== X-Google-Smtp-Source: ABdhPJwJ1FMdhW0jHz7DXfH+KVJFXvSxTzvgklCFyexaWLl69lIesWnNkxlOzw22YhI7Gz8v20BzA4cyotU5Kzyzvb4= X-Received: by 2002:a17:90b:1087:: with SMTP id gj7mr343606pjb.41.1610475082106; Tue, 12 Jan 2021 10:11:22 -0800 (PST) MIME-Version: 1.0 References: <0f20f867d747b678604a68173a5f20fb8df9b756.1609871239.git.andreyknvl@google.com> In-Reply-To: From: Andrey Konovalov Date: Tue, 12 Jan 2021 19:11:10 +0100 Message-ID: Subject: Re: [PATCH 04/11] kasan: add match-all tag tests To: Marco Elver Cc: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Andrew Morton , Will Deacon , Andrey Ryabinin , 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 Tue, Jan 12, 2021 at 2:17 PM Marco Elver wrote: > > On Tue, Jan 05, 2021 at 07:27PM +0100, 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. > > > > Signed-off-by: Andrey Konovalov > > Link: https://linux-review.googlesource.com/id/I78f1375efafa162b37f3abcb2c5bc2f3955dfd8e > > --- > > lib/test_kasan.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++ > > mm/kasan/kasan.h | 6 ++++ > > 2 files changed, 99 insertions(+) > > > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > > index 46e578c8e842..f1eda0bcc780 100644 > > --- a/lib/test_kasan.c > > +++ b/lib/test_kasan.c > > @@ -13,6 +13,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -790,6 +791,95 @@ static void vmalloc_oob(struct kunit *test) > > vfree(area); > > } > > > > +/* > > + * Check that match-all pointer tag is not assigned randomly for > > + * tag-based modes. > > + */ > > +static void match_all_not_assigned(struct kunit *test) > > +{ > > + char *ptr; > > + struct page *pages; > > + int i, size, order; > > + > > + for (i = 0; i < 256; i++) { > > + size = get_random_int() % KMALLOC_MAX_SIZE; > > size appears to be unused? Indeed, will fix in v2, thanks! > > > + 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); > > + 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_NE(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; > > + > > + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) { > > + kunit_info(test, "skipping, CONFIG_KASAN_SW/HW_TAGS required"); > > + return; > > + } > > + > > + 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; > > + > > + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) { > > + kunit_info(test, "skipping, CONFIG_KASAN_SW/HW_TAGS required"); > > + return; > > + } > > + > > + 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), > > @@ -829,6 +919,9 @@ 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 */ > > -- > > 2.29.2.729.g45daf8777d-goog > >