From patchwork Fri Jan 15 17:52:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 12023549 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=-16.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 8D8F1C433E0 for ; Fri, 15 Jan 2021 17:53:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 22398221FA for ; Fri, 15 Jan 2021 17:53:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22398221FA 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 B687C8D01CA; Fri, 15 Jan 2021 12:53:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AF0CA8D01CB; Fri, 15 Jan 2021 12:53:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9428F8D01CA; Fri, 15 Jan 2021 12:53:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0039.hostedemail.com [216.40.44.39]) by kanga.kvack.org (Postfix) with ESMTP id 749178D01C7 for ; Fri, 15 Jan 2021 12:53:13 -0500 (EST) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3C29B18128703 for ; Fri, 15 Jan 2021 17:53:13 +0000 (UTC) X-FDA: 77708755866.02.twist98_5d08bfa27531 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id 1B1FE101913DD for ; Fri, 15 Jan 2021 17:53:13 +0000 (UTC) X-HE-Tag: twist98_5d08bfa27531 X-Filterd-Recvd-Size: 8291 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Fri, 15 Jan 2021 17:53:12 +0000 (UTC) Received: by mail-wr1-f74.google.com with SMTP id o17so4467465wra.8 for ; Fri, 15 Jan 2021 09:53:12 -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=jfWJXOWlHJo7EltzDAfS0s8ib651kGruxNglu567YtE=; b=UpDZIP6xR7ghSKnhzK0eRNfsLeyL8ZfbfdrS0ZbiXAREa4/3evrQBC1aIzqQ9uPRaK vVDx5+guFDF2M60tFhWxTC1woCdY3Ezi3z80HIkXlN5A4QRMNh+us9qm3WvBz4r9xUAX vEAGJhsJXcf8yq/65SZe1JFLuzjSlkMBF9WzIOAjE8C/oevNO9sxdMzCxd5wddJ/kDN+ 9t+r4P24kGbGCAeo2xPmV1rZqyp078zmHZoPN+wLHN40Pe0Nxa6wDDbvBnCBuiIPX3nz 8SPXVztg5pBePTNl2c0MLwzMTfKqUuDsyxcShY8oKJqSH+0VXX9dD8lLPltgiEwTTtmt yBvQ== 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=jfWJXOWlHJo7EltzDAfS0s8ib651kGruxNglu567YtE=; b=BEri6RpSaw2EYZl1Rghy5l1GGiulky2YcoIjEoWLC6xZRHrPrvY+KwMz3GD2+BbLAb knOk1UfYpAP6XM4OyzDeUWiohokwSuF9EegWU+4TxcMoFUSOZln23XBYPaA1FRygQGDT uO5xn05SD1FIsNEQVoJRII3Uj5na8UVdLv8mgkB5MWBOzid/l3t4lMtMteJlkgVuVRew jgUNhzUJff9igoko41y5CVa2lsO9ZTBwWDKRmyj4KUaZ/3SMqwnJluVLRF0DPV0CPuRM 4SIi20HLy2MP3PgYqfixW8NUTF+RfOYIR4qyujeyQsyHcHt2mti3Xaj2IRCS80ZutT5W FjEg== X-Gm-Message-State: AOAM533LWNDVckOViTHtq8M5w0Ov95L/AIQzI9SpFFmamSKo6W3/AMM1 nK8Fm5dMEPxldPF3tce5+VdVw24wzP3tUwYb X-Google-Smtp-Source: ABdhPJyTX+oi4bC453jP1Oba8mmIO/be705slN5QNgbNBVtZKN7OlSl3vgP/jlwXwIICnGDefo9UkGtGOwwhdtkR X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:7220:84ff:fe09:7e9d]) (user=andreyknvl job=sendgmr) by 2002:a1c:e919:: with SMTP id q25mr2033205wmc.57.1610733191375; Fri, 15 Jan 2021 09:53:11 -0800 (PST) Date: Fri, 15 Jan 2021 18:52:42 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH v4 05/15] kasan: add match-all tag 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 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: 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 Reviewed-by: Marco Elver Reviewed-by: Alexander Potapenko Signed-off-by: Andrey Konovalov --- 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..c344fe506ffc 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) + 1; + 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) + 1; + 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 */