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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6EB44C433EF for ; Thu, 2 Sep 2021 21:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BD5560E8B for ; Thu, 2 Sep 2021 21:57:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347668AbhIBV6u (ORCPT ); Thu, 2 Sep 2021 17:58:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:54436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243139AbhIBV6t (ORCPT ); Thu, 2 Sep 2021 17:58:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B491C603E9; Thu, 2 Sep 2021 21:57:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1630619871; bh=LH23rYAMM7Yu63m2eQE9V2jZfCidGPaykUeeVUGn/aQ=; h=Date:From:To:Subject:In-Reply-To:From; b=LakSgsHHPCxaaDrsFKrtSfSwbYm3YIaz2WC2SHljDtb5etExtsFxO2Y1c9ITwmbs5 0x5D5ZM3bc8tmXdfzMdORulzWV58IaYc/PNA+CRohPafZH41rwzs19S18f/QSTtL/i /ahQihsYXv9r34N8ZEsSy2BgPlxQudVwIRGJyuhA= Date: Thu, 02 Sep 2021 14:57:50 -0700 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@gmail.com, aryabinin@virtuozzo.com, dvyukov@google.com, elver@google.com, glider@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 148/212] kasan: test: avoid corrupting memory in copy_user_test Message-ID: <20210902215750.wLivJzDYL%akpm@linux-foundation.org> In-Reply-To: <20210902144820.78957dff93d7bea620d55a89@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Konovalov Subject: kasan: test: avoid corrupting memory in copy_user_test copy_user_test() does writes past the allocated object. As the result, it corrupts kernel memory, which might lead to crashes with the HW_TAGS mode, as it neither uses quarantine nor redzones. (Technically, this test can't yet be enabled with the HW_TAGS mode, but this will be implemented in the future.) Adjust the test to only write memory within the aligned kmalloc object. Link: https://lkml.kernel.org/r/19bf3a5112ee65b7db88dc731643b657b816c5e8.1628779805.git.andreyknvl@gmail.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Signed-off-by: Andrew Morton --- lib/test_kasan_module.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) --- a/lib/test_kasan_module.c~kasan-test-avoid-corrupting-memory-in-copy_user_test +++ a/lib/test_kasan_module.c @@ -15,13 +15,11 @@ #include "../mm/kasan/kasan.h" -#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) - static noinline void __init copy_user_test(void) { char *kmem; char __user *usermem; - size_t size = 10; + size_t size = 128 - KASAN_GRANULE_SIZE; int __maybe_unused unused; kmem = kmalloc(size, GFP_KERNEL); @@ -38,25 +36,25 @@ static noinline void __init copy_user_te } pr_info("out-of-bounds in copy_from_user()\n"); - unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); + unused = copy_from_user(kmem, usermem, size + 1); pr_info("out-of-bounds in copy_to_user()\n"); - unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); + unused = copy_to_user(usermem, kmem, size + 1); pr_info("out-of-bounds in __copy_from_user()\n"); - unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); + unused = __copy_from_user(kmem, usermem, size + 1); pr_info("out-of-bounds in __copy_to_user()\n"); - unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF); + unused = __copy_to_user(usermem, kmem, size + 1); pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); - unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF); + unused = __copy_from_user_inatomic(kmem, usermem, size + 1); pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); - unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF); + unused = __copy_to_user_inatomic(usermem, kmem, size + 1); pr_info("out-of-bounds in strncpy_from_user()\n"); - unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF); + unused = strncpy_from_user(kmem, usermem, size + 1); vm_munmap((unsigned long)usermem, PAGE_SIZE); kfree(kmem); _