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=-5.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 F1F1AC4724C for ; Fri, 1 May 2020 06:57:31 +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 C544E2070B for ; Fri, 1 May 2020 06:57:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C544E2070B 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]:57224 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUPc2-0007XI-TX for qemu-devel@archiver.kernel.org; Fri, 01 May 2020 02:57:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45588) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUPbA-00076T-Rt for qemu-devel@nongnu.org; Fri, 01 May 2020 02:56:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jUPbA-0003iz-01 for qemu-devel@nongnu.org; Fri, 01 May 2020 02:56:36 -0400 Received: from indium.canonical.com ([91.189.90.7]:54174) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jUPb9-0003eM-Gg for qemu-devel@nongnu.org; Fri, 01 May 2020 02:56:35 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1jUPb7-0000q7-Gd for ; Fri, 01 May 2020 06:56:33 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 7440A2E810C for ; Fri, 1 May 2020 06:56:33 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 01 May 2020 06:47:12 -0000 From: =?utf-8?q?Christian_Ehrhardt_=EE=83=BF?= <1749393@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Fix Released; importance=Undecided; assignee=None; X-Launchpad-Bug: distribution=ubuntu; sourcepackage=qemu; component=main; status=Triaged; importance=Undecided; assignee=rth@twiddle.net; X-Launchpad-Bug-Tags: arm linux-user qemu-20.10 X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: doko gerard-f-vidal-4 hertzog janitor laurent-vivier paelzer peterogden pmaydell rth X-Launchpad-Bug-Reporter: =?utf-8?q?Rapha=C3=ABl_Hertzog_=28hertzog=29?= X-Launchpad-Bug-Modifier: =?utf-8?q?Christian_Ehrhardt_=EE=83=BF_=28paelzer?= =?utf-8?q?=29?= References: <151859702399.9461.6832978283203997178.malonedeb@chaenomeles.canonical.com> Message-Id: <158831563276.13979.12202053518555221631.malone@gac.canonical.com> Subject: [Bug 1749393] Re: sbrk() not working under qemu-user with a PIE-compiled binary? 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="fbdff7602bd10fb883bf7e2ddcc7fd5a16f60398"; Instance="production-secrets-lazr.conf" X-Launchpad-Hash: 4a373de1bf9d1e8f4ba2bca36dd649008a7fe59c Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/01 02:56:34 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Received-From: 91.189.90.7 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 1749393 <1749393@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Will be merged in 20.10 with qemu >=3D5.0 where this came upstream. ** Tags added: qemu-20.10 ** Changed in: qemu (Ubuntu) Status: Confirmed =3D> Triaged -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1749393 Title: sbrk() not working under qemu-user with a PIE-compiled binary? Status in QEMU: Fix Released Status in qemu package in Ubuntu: Triaged Bug description: In Debian unstable, we recently switched bash to be a PIE-compiled binary (for hardening). Unfortunately this resulted in bash being broken when run under qemu-user (for all target architectures, host being amd64 for me). $ sudo chroot /srv/chroots/sid-i386/ qemu-i386-static /bin/bash bash: xmalloc: .././shell.c:1709: cannot allocate 10 bytes (0 bytes alloc= ated) bash has its own malloc implementation based on sbrk(): https://git.savannah.gnu.org/cgit/bash.git/tree/lib/malloc/malloc.c When we disable this internal implementation and rely on glibc's malloc, then everything is fine. But it might be that glibc has a fallback when sbrk() is not working properly and it might hide the underlying problem in qemu-user. This issue has also been reported to the bash upstream author and he sugg= ested that the issue might be in qemu-user so I'm opening a ticket here. He= re's the discussion with the bash upstream author: https://lists.gnu.org/archive/html/bug-bash/2018-02/threads.html#00080 You can find the problematic bash binary in that .deb file: http://snapshot.debian.org/archive/debian/20180206T154716Z/pool/main/b/ba= sh/bash_4.4.18-1_i386.deb The version of qemu I have been using is 2.11 (Debian package qemu- user-static version 1:2.11+dfsg-1) but I have had reports that the problem is reproducible with older versions (back to 2.8 at least). Here are the related Debian bug reports: https://bugs.debian.org/889869 https://bugs.debian.org/865599 It's worth noting that bash used to have this problem (when compiled as a= PIE binary) even when run directly but then something got fixed in the ker= nel and now the problem only appears when run under qemu-user: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518483 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1749393/+subscriptions