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=-23.2 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=unavailable 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 2F4E8C4338F for ; Thu, 12 Aug 2021 08:51:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 154BA61019 for ; Thu, 12 Aug 2021 08:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235403AbhHLIvZ (ORCPT ); Thu, 12 Aug 2021 04:51:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54534 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235260AbhHLIvT (ORCPT ); Thu, 12 Aug 2021 04:51:19 -0400 Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E80A8C061765 for ; Thu, 12 Aug 2021 01:50:54 -0700 (PDT) Received: by mail-ot1-x336.google.com with SMTP id n1-20020a9d1e810000b0290514da4485e4so4113454otn.4 for ; Thu, 12 Aug 2021 01:50:54 -0700 (PDT) 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=L6hRQLk+mDuzM1tU9wPV9OpAoS0YdU979SiyLqR9lWg=; b=tNp1TxiRYJy2MGgWr4EvL6owOqgDQyzN2IUYbSgj6mySD33StDfMV/dKqh4aO3NRDu 3fSLh2Eh3w/3meKn++MDnyTHzyFbFHyVUHXVk02nIg3UuMrNNG+/93O59Qo/Q9X2VCkD 5XUy44q/T6C48y8mwrqwNmJ3+s0gRrUWcw6vLmOcWrpj59UL6t9inlLQ0L9i5Fjtr7ya rHUu+umhvG9bK0WvdEAQPc/ibl3+0GOOazlluG4JEzAFJO73r6on2N7zHPp8BEBcqyXM H/hQhbwVkqMeoRSHL4ZeXcYb0H9l+x03uOZkManey/4y46Zez7ige0/4dzrm5fVvo3c3 YoLw== 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=L6hRQLk+mDuzM1tU9wPV9OpAoS0YdU979SiyLqR9lWg=; b=lmLlQDNdA1ARn212Gib/Zht+M26mPbH4OdNYdQNHgYEqgTN9wl42ITNObXlyv3Itc5 HasWVMJproAMPujEWo0ojYEmjhwWXQ3MO1WDvo5xEbwnvQXWrpFhHxXZkEqayGPHcn9S HeOOdtYMOEFgh/KLmV5D2COV1x9fXsgoLBdZkxukqeSwweUmI/weTAzluhTuYGu2Wno5 6mthx3IxQYPIN9HOkIKbF0dV77LlA3XuwNwXpgZfPxM5Ux97fHttFsTJTigSWfACWn6E YJTn/Vow39hc0lc8f+BjyqBx0PCN8kRAdnNuyfvK0SjMZWI2k2LXvCbX5pZpfI6tA2/v h6FA== X-Gm-Message-State: AOAM532spoTlbv685Yzotw+tXL9AwAj0HKQ5jpBkOCSFwtdzzKoz7c9u V1wHOEzTfJGmT/65jx+O9OttY1uJsw0l/UEFCFIGAw== X-Google-Smtp-Source: ABdhPJxREciDWAvw2hXJoSNgwGzwAgfrsH/9ESk5Gp+0a5WDvKPxkb7At1Mz00fE9R8WAj7OmLftA00Br1JhwbCe4D4= X-Received: by 2002:a9d:d04:: with SMTP id 4mr2681205oti.251.1628758254073; Thu, 12 Aug 2021 01:50:54 -0700 (PDT) MIME-Version: 1.0 References: <17b812a3c28024acfca9b1a9e45c8235b35efa32.1628709663.git.andreyknvl@gmail.com> In-Reply-To: <17b812a3c28024acfca9b1a9e45c8235b35efa32.1628709663.git.andreyknvl@gmail.com> From: Marco Elver Date: Thu, 12 Aug 2021 10:50:42 +0200 Message-ID: Subject: Re: [PATCH 7/8] kasan: test: avoid corrupting memory in copy_user_test To: andrey.konovalov@linux.dev Cc: Andrew Morton , Andrey Konovalov , Andrey Ryabinin , Dmitry Vyukov , Alexander Potapenko , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Aug 2021 at 21:30, wrote: > From: Andrey Konovalov > > 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. > > Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver > --- > lib/test_kasan_module.c | 18 ++++++++---------- > 1 file changed, 8 insertions(+), 10 deletions(-) > > diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c > index f1017f345d6c..fa73b9df0be4 100644 > --- a/lib/test_kasan_module.c > +++ b/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_test(void) > } > > 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); > -- > 2.25.1 >