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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 E2BEBC433B4 for ; Wed, 7 Apr 2021 21:36:47 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E8BC061205 for ; Wed, 7 Apr 2021 21:36:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8BC061205 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39110 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lUFqv-0000Ho-UO for qemu-devel@archiver.kernel.org; Wed, 07 Apr 2021 17:36:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47832) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lUFpr-000850-L3 for qemu-devel@nongnu.org; Wed, 07 Apr 2021 17:35:40 -0400 Received: from indium.canonical.com ([91.189.90.7]:33700) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lUFpo-0006kM-5K for qemu-devel@nongnu.org; Wed, 07 Apr 2021 17:35:39 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1lUFpk-0007CI-FY for ; Wed, 07 Apr 2021 21:35:32 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 74BB02E8047 for ; Wed, 7 Apr 2021 21:35:32 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 07 Apr 2021 21:29:51 -0000 From: =?utf-8?q?Alex_Benn=C3=A9e?= <1921948@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=In Progress; importance=Undecided; assignee=rth@twiddle.net; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: ajbennee pcc-goog rth xairy X-Launchpad-Bug-Reporter: Andrey Konovalov (xairy) X-Launchpad-Bug-Modifier: =?utf-8?q?Alex_Benn=C3=A9e_=28ajbennee=29?= References: <161713286145.25906.15042270704525675392.malonedeb@wampee.canonical.com> <161782908442.29743.17585290508436200821.malone@gac.canonical.com> Message-ID: <874kghvl2s.fsf@linaro.org> Subject: Re: [Bug 1921948] Re: MTE tags not checked properly for unaligned accesses at EL1 X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="57f1f603f707b9cfa764cae8dd0f3999026b4763"; Instance="production" X-Launchpad-Hash: 107da7dc051ad8006aed0518563bcc94f241baa3 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1921948 <1921948@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20210407212951.G2Q8xyXvO-1_8nbukMCuqVxwfK2jNXqMqbNmeV7ZIqc@z> Andrey Konovalov <1921948@bugs.launchpad.net> writes: > Is this with QEMU master without the patches mentioned in this bug? This is with Richard's latest series. > > Which kernel version do you use? v5.11 > Could you share your kernel config? We are just testing with Richard's config and eliminating compiler shenanigans now. -- = Alex Benn=C3=A9e -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1921948 Title: MTE tags not checked properly for unaligned accesses at EL1 Status in QEMU: In Progress Bug description: For kernel memory accesses that span across two memory granules, QEMU's MTE implementation only checks the tag of the first granule but not of the second one. To reproduce this, build the Linux kernel with CONFIG_KASAN_HW_TAGS enabled, apply the patch below, and boot the kernel: diff --git a/sound/last.c b/sound/last.c index f0bb98780e70..04745cb30b74 100644 --- a/sound/last.c +++ b/sound/last.c @@ -5,12 +5,18 @@ */ = #include +#include #include = static int __init alsa_sound_last_init(void) { struct snd_card *card; int idx, ok =3D 0; + + char *ptr =3D kmalloc(128, GFP_KERNEL); + pr_err("KASAN report should follow:\n"); + *(volatile unsigned long *)(ptr + 124); + kfree(ptr); = printk(KERN_INFO "ALSA device list:\n"); for (idx =3D 0; idx < SNDRV_CARDS; idx++) { KASAN tags the 128 allocated bytes with the same tag as the returned pointer. The memory granule that follows the 128 allocated bytes has a different tag (with 1/15 probability). Expected result: a tag fault is detected and a KASAN report is printed wh= en accessing bytes [124, 130). Observed result: no tag fault is detected and no KASAN report is printed. Here are the flags that I use to run QEMU if they matter: qemu-system-aarch64 -s -machine virt,mte=3Don -cpu max -m 2G -smp 2 -net user,host=3D10.0.2.10,hostfwd=3Dtcp:127.0.0.1:10021-:22 -net nic -nographic -kernel ./Image -append "console=3DttyAMA0 root=3D/dev/vda earlyprintk=3Dserial" -drive file=3D./fs.img,format=3Draw,if=3Dvirtio -no- shutdown -no-reboot To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1921948/+subscriptions