From nobody Sat Dec 27 22:57:32 2025 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 E915BC4167B for ; Thu, 14 Dec 2023 16:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229595AbjLNQo3 (ORCPT ); Thu, 14 Dec 2023 11:44:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229487AbjLNQo1 (ORCPT ); Thu, 14 Dec 2023 11:44:27 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C817E120 for ; Thu, 14 Dec 2023 08:44:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702572273; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=w7n7C7cUVujGrFjhyS4KsTPPgLzIdfsh/gqlYQrUTfI=; b=f6pGycap9gnekhMLWhtWin6FhGYFQkIUvuw1tI9mmAnD5KPgF4rT0gaQE6FVFLbcy2Fp8g HfMwGUdIXAVDgjfXyTpI/+baVFvKZDu3SkhtR0fKWduy7256GSyl3pcpv3j/qPskP8ev7+ 6ehZGGw+eOJeBAoR4GbRf25azGK8roM= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-212-7MArNrfxMKKcVf6uYur6ow-1; Thu, 14 Dec 2023 11:44:27 -0500 X-MC-Unique: 7MArNrfxMKKcVf6uYur6ow-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D7D91C0514E; Thu, 14 Dec 2023 16:44:26 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.22.33.120]) by smtp.corp.redhat.com (Postfix) with ESMTP id 28381492BC6; Thu, 14 Dec 2023 16:44:25 +0000 (UTC) From: Nico Pache To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com Cc: akpm@linux-foundation.org, vincenzo.frascino@arm.com, dvyukov@google.com, andreyknvl@gmail.com, glider@google.com, ryabinin.a.a@gmail.com Subject: [PATCH v2] kunit: kasan_test: disable fortify string checker on kmalloc_oob_memset Date: Thu, 14 Dec 2023 09:44:23 -0700 Message-ID: <20231214164423.6202-1-npache@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" similar to commit 09c6304e38e4 ("kasan: test: fix compatibility with FORTIFY_SOURCE") the kernel is panicing in kmalloc_oob_memset_*. This is due to the `ptr` not being hidden from the optimizer which would disable the runtime fortify string checker. kernel BUG at lib/string_helpers.c:1048! Call Trace: [<00000000272502e2>] fortify_panic+0x2a/0x30 ([<00000000272502de>] fortify_panic+0x26/0x30) [<001bffff817045c4>] kmalloc_oob_memset_2+0x22c/0x230 [kasan_test] Hide the `ptr` variable from the optimizer to fix the kernel panic. Also define a memset_size variable and hide that as well. This cleans up the code and follows the same convention as other tests. Signed-off-by: Nico Pache Reviewed-by: Andrey Konovalov --- mm/kasan/kasan_test.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c index 8281eb42464b..34515a106ca5 100644 --- a/mm/kasan/kasan_test.c +++ b/mm/kasan/kasan_test.c @@ -493,14 +493,17 @@ static void kmalloc_oob_memset_2(struct kunit *test) { char *ptr; size_t size =3D 128 - KASAN_GRANULE_SIZE; + size_t memset_size =3D 2; =20 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); =20 ptr =3D kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); =20 + OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2)); + OPTIMIZER_HIDE_VAR(memset_size); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, memset_size)); kfree(ptr); } =20 @@ -508,14 +511,17 @@ static void kmalloc_oob_memset_4(struct kunit *test) { char *ptr; size_t size =3D 128 - KASAN_GRANULE_SIZE; + size_t memset_size =3D 4; =20 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); =20 ptr =3D kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); =20 + OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4)); + OPTIMIZER_HIDE_VAR(memset_size); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, memset_size)); kfree(ptr); } =20 @@ -523,14 +529,17 @@ static void kmalloc_oob_memset_8(struct kunit *test) { char *ptr; size_t size =3D 128 - KASAN_GRANULE_SIZE; + size_t memset_size =3D 8; =20 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); =20 ptr =3D kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); =20 + OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8)); + OPTIMIZER_HIDE_VAR(memset_size); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, memset_size)); kfree(ptr); } =20 @@ -538,14 +547,17 @@ static void kmalloc_oob_memset_16(struct kunit *test) { char *ptr; size_t size =3D 128 - KASAN_GRANULE_SIZE; + size_t memset_size =3D 16; =20 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); =20 ptr =3D kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); =20 + OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16)); + OPTIMIZER_HIDE_VAR(memset_size); + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, memset_size)); kfree(ptr); } =20 --=20 2.43.0