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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C6C3E7C4F3 for ; Wed, 4 Oct 2023 20:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244106AbjJDUTT (ORCPT ); Wed, 4 Oct 2023 16:19:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244031AbjJDUTF (ORCPT ); Wed, 4 Oct 2023 16:19:05 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 213A793 for ; Wed, 4 Oct 2023 13:19:02 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83C69C433CA; Wed, 4 Oct 2023 20:19:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1696450741; bh=4RvW4CvqgDkSB2r6fOfCdy//s+TGMQnngzXFU+0TA7Y=; h=Date:To:From:Subject:From; b=bZxfLOmjlqSTyDz+oWORrjkGCimzMP+KX/Rs4q5fs/lToS4DzzOpbxI79ERo4LWb2 9f4SVtgzbSmyqTTy3vzUD2Havfr8/TOI6qzqDA1c+0pL0RT3lDKH7ecuNSABePWLak GfhmhhDsPNIrEK40H4JIXCaELdiH9Fsk8KYKToJY= Date: Wed, 04 Oct 2023 13:19:00 -0700 To: mm-commits@vger.kernel.org, elver@google.com, dvyukov@google.com, glider@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] kmsan-introduce-test_memcpy_initialized_gap.patch removed from -mm tree Message-Id: <20231004201901.83C69C433CA@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: kmsan: introduce test_memcpy_initialized_gap() has been removed from the -mm tree. Its filename was kmsan-introduce-test_memcpy_initialized_gap.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Alexander Potapenko Subject: kmsan: introduce test_memcpy_initialized_gap() Date: Mon, 11 Sep 2023 16:57:02 +0200 Add a regression test for the special case where memcpy() previously failed to correctly set the origins: if upon memcpy() four aligned initialized bytes with a zero origin value ended up split between two aligned four-byte chunks, one of those chunks could've received the zero origin value even despite it contained uninitialized bytes from other writes. Link: https://lkml.kernel.org/r/20230911145702.2663753-4-glider@google.com Signed-off-by: Alexander Potapenko Suggested-by: Marco Elver Acked-by: Marco Elver Cc: Dmitry Vyukov Signed-off-by: Andrew Morton --- mm/kmsan/kmsan_test.c | 53 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) --- a/mm/kmsan/kmsan_test.c~kmsan-introduce-test_memcpy_initialized_gap +++ a/mm/kmsan/kmsan_test.c @@ -486,6 +486,58 @@ static void test_memcpy_aligned_to_unali KUNIT_EXPECT_TRUE(test, report_matches(&expect)); } +/* + * Test case: ensure that origin slots do not accidentally get overwritten with + * zeroes during memcpy(). + * + * Previously, when copying memory from an aligned buffer to an unaligned one, + * if there were zero origins corresponding to zero shadow values in the source + * buffer, they could have ended up being copied to nonzero shadow values in the + * destination buffer: + * + * memcpy(0xffff888080a00000, 0xffff888080900002, 8) + * + * src (0xffff888080900002): ..xx .... xx.. + * src origins: o111 0000 o222 + * dst (0xffff888080a00000): xx.. ..xx + * dst origins: o111 0000 + * (or 0000 o222) + * + * (here . stands for an initialized byte, and x for an uninitialized one. + * + * Ensure that this does not happen anymore, and for both destination bytes + * the origin is nonzero (i.e. KMSAN reports an error). + */ +static void test_memcpy_initialized_gap(struct kunit *test) +{ + EXPECTATION_UNINIT_VALUE_FN(expect, "test_memcpy_initialized_gap"); + volatile char uninit_src[12]; + volatile char dst[8] = { 0 }; + + kunit_info( + test, + "unaligned 4-byte initialized value gets a nonzero origin after memcpy() - (2 UMR reports)\n"); + + uninit_src[0] = 42; + uninit_src[1] = 42; + uninit_src[4] = 42; + uninit_src[5] = 42; + uninit_src[6] = 42; + uninit_src[7] = 42; + uninit_src[10] = 42; + uninit_src[11] = 42; + memcpy_noinline((void *)&dst[0], (void *)&uninit_src[2], 8); + + kmsan_check_memory((void *)&dst[0], 4); + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); + report_reset(); + kmsan_check_memory((void *)&dst[2], 4); + KUNIT_EXPECT_FALSE(test, report_matches(&expect)); + report_reset(); + kmsan_check_memory((void *)&dst[4], 4); + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); +} + /* Generate test cases for memset16(), memset32(), memset64(). */ #define DEFINE_TEST_MEMSETXX(size) \ static void test_memset##size(struct kunit *test) \ @@ -579,6 +631,7 @@ static struct kunit_case kmsan_test_case KUNIT_CASE(test_init_memcpy), KUNIT_CASE(test_memcpy_aligned_to_aligned), KUNIT_CASE(test_memcpy_aligned_to_unaligned), + KUNIT_CASE(test_memcpy_initialized_gap), KUNIT_CASE(test_memset16), KUNIT_CASE(test_memset32), KUNIT_CASE(test_memset64), _ Patches currently in -mm which might be from glider@google.com are