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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 24E4CC432BE for ; Thu, 12 Aug 2021 12:55:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E532B6103E for ; Thu, 12 Aug 2021 12:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237559AbhHLMzz (ORCPT ); Thu, 12 Aug 2021 08:55:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236506AbhHLMzy (ORCPT ); Thu, 12 Aug 2021 08:55:54 -0400 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31D77C061765 for ; Thu, 12 Aug 2021 05:55:29 -0700 (PDT) Received: by mail-ej1-x62c.google.com with SMTP id bq25so1341345ejb.11 for ; Thu, 12 Aug 2021 05:55:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=hetAWS8vJTkbvJ1Yuh2ecULwYt0HQ0q3zS2e3QmOOk0=; b=VX3lXUncEAiMWCQXnnXyzQhXlgIUCn+99sQZAdcGcSPeCwxoiBQLOYxunMYCp2evFy PvDkaahs2fIVWzYkjnfhqbuT/TcmSgbaRkPDb4/gXnbSiXAHh+q/HnERGAinmqLS6Z0s 2nqvrzAq2/PAi5rpwaOdTGc+2B9oPKwBy+xyeSL6nEAbvcgKGZMkdIT+Npq4HeHqU4NR Ro5GOsX/6ci3aDRIg+zaloKpMkD08g1hXxTdo9pZzGp14KV/8bx+DC72UUAtDAOQJKxM uwkBkhURpaVyyIGy9UYYIepFjRFXXsI9BEAsjiFRyz+VCdDKsFXzjC9P2SLrLM5h4891 yZaQ== 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=hetAWS8vJTkbvJ1Yuh2ecULwYt0HQ0q3zS2e3QmOOk0=; b=WiHsC1zReVKgRQ5Vb4fPI1YUUYTFXcBuHmaOb5GFQXTRJTMY9MD840CZ27w8fudrWj owwWFRBrEUiAseIZT+ffR2iXRcO5fxH8o++ZcxU+1AjRaGn9DprjQBf9ZjberaNiHj5X kIJHZeOguLzOAP1tSzxChXQVZ+G3FszWmAzYFsvWWnNRR6o+PHEYrPHTIREEWakOVIr3 msWVGevBfUsAm4I3B6gTERiHPHVDqGsVSe1paPJPyaZJCe8vfKAztt29IE35Ad6pPFM+ 1YkrSiEq676X41qTY/0X7CKnrnveUSayJp+Hcp32l0y2zekzu+IXpUwzMZvQYx+xxc7E NhwQ== X-Gm-Message-State: AOAM532dPSBbZb7jkY8aDzG93CKkWb2QPLXPDdVMUR6Q9TCULJkqr6a9 7bpDjgt+3G2Bai4ZxQrnR38qAxTKTo6ATkMXjs4= X-Google-Smtp-Source: ABdhPJwUGAz+StzvFe3sEKadoMqkzkGxIfpbIgPqcHNBMpIUdAiRvhJvJxHF1csdmHpux4meRLpWTdAZ/DWt3/yVCko= X-Received: by 2002:a17:906:d147:: with SMTP id br7mr3613564ejb.126.1628772927836; Thu, 12 Aug 2021 05:55:27 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Andrey Konovalov Date: Thu, 12 Aug 2021 14:55:16 +0200 Message-ID: Subject: Re: [PATCH 3/8] kasan: test: avoid corrupting memory via memset To: Marco Elver Cc: andrey.konovalov@linux.dev, Andrew Morton , Andrey Ryabinin , Dmitry Vyukov , Alexander Potapenko , kasan-dev , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 12, 2021 at 10:57 AM Marco Elver wrote: > > On Wed, 11 Aug 2021 at 21:21, wrote: > > From: Andrey Konovalov > > > > kmalloc_oob_memset_*() tests do writes past the allocated objects. > > As the result, they corrupt memory, which might lead to crashes with the > > HW_TAGS mode, as it neither uses quarantine nor redzones. > > > > Adjust the tests to only write memory within the aligned kmalloc objects. > > > > Signed-off-by: Andrey Konovalov > > --- > > lib/test_kasan.c | 22 +++++++++++----------- > > 1 file changed, 11 insertions(+), 11 deletions(-) > > > > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > > index c82a82eb5393..fd00cd35e82c 100644 > > --- a/lib/test_kasan.c > > +++ b/lib/test_kasan.c > > @@ -431,61 +431,61 @@ static void kmalloc_uaf_16(struct kunit *test) > > static void kmalloc_oob_memset_2(struct kunit *test) > > { > > char *ptr; > > - size_t size = 8; > > + size_t size = 128 - KASAN_GRANULE_SIZE; > > > > ptr = kmalloc(size, GFP_KERNEL); > > KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > > > > - KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2)); > > + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size, 0, 2)); > > I think one important aspect of these tests in generic mode is that > the written range touches both valid and invalid memory. I think that > was meant to test any explicit instrumentation isn't just looking at > the starting address, but at the whole range. Good point! > It seems that with these changes that is no longer tested. Could we > somehow make it still test that? Yes, will do in v2. Thanks, Marco!