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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 761FEC433DF for ; Mon, 29 Jun 2020 19:02:43 +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 42E7020663 for ; Mon, 29 Jun 2020 19:02:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="mfvkRgLM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42E7020663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50842 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jpz3C-0001oF-I9 for qemu-devel@archiver.kernel.org; Mon, 29 Jun 2020 15:02:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45444) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jpz1R-0000fE-Rv for qemu-devel@nongnu.org; Mon, 29 Jun 2020 15:00:53 -0400 Received: from mail-wm1-x331.google.com ([2a00:1450:4864:20::331]:37474) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jpz1M-0006k8-O1 for qemu-devel@nongnu.org; Mon, 29 Jun 2020 15:00:53 -0400 Received: by mail-wm1-x331.google.com with SMTP id o2so17156084wmh.2 for ; Mon, 29 Jun 2020 12:00:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:user-agent:from:to:cc:subject:in-reply-to:date :message-id:mime-version:content-transfer-encoding; bh=H2dqSMC8xHqPnX99k29N87b3vP+L+ekA78ODI4l+FgQ=; b=mfvkRgLMsWli+It1TbiwbI5QuRb0v/adpt7eyT+UvhyEWi3lZouE4Jla+Yf0ofSVrT wZrpWGMUtzdyjtaohrC8C2yreebUApMy+nE3T/yKU2ly/TxbibZ8g4xLwjuSGupZRF63 +mDeJ2NiX/NCoMBMYtxQCzoY43FC5f12C8hv5nxP7cclirOmiw4WIMIg5hieATqNjmco gJ4c0GTEBnrLBn4JEyTC/VdUIDa9fXQplEJcZFEubd/NNrk8+D7w5zTyKk/ZAPawxahD hbXJKhpEyeUm6Sh1ADVE9NzcVGDxb4Lsuk9ou7DjKKkxpTaEdnSGdcL6lfGqrr7yi4A8 ZXgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version:content-transfer-encoding; bh=H2dqSMC8xHqPnX99k29N87b3vP+L+ekA78ODI4l+FgQ=; b=q84imSHdeSHWMjRxfd3siTmmvG/1JfQRFLiEiV1JunwipmANtOZ1lRxw2hluzcdkKj lLis0woiOhkRtRgL/Mg//CkC5DUftww4VlYICABm/IJ1wkNOTt/cGWOfVmQvhfHe0F9A oaLPRJqFLt6RVXYSaNmDzMljYjYwCGvrGIr1AYoW809+ZvxliEi6FKRDWa1Li1b97rcs rUOGR/kk+lioyEwzbzzu4cYWnVXT5gj08HJ9Ke08UUBvAQjOgLcExLrdJLujiskYhEiO ExtxJmBtDPsgWX0zCEs+7n6mUR81fwvzboGJRTdKiNrLC9bzquKLYt0sFqbScD3xrWQr FR0w== X-Gm-Message-State: AOAM533dkAMfacdOgT0N5XpMyKwo6P9B7icybm8VMy7Fn3aqaTCs+VsZ y1NCP20M4/KemmhjOZBPELZ1t98Q7EU= X-Google-Smtp-Source: ABdhPJxMCg6xAtpZPdFJgxzk5AYzFl8JetGW7D6GkD2J+2AEJHPYwQ63hhtLXby1+ZeWzyrn/rWdbw== X-Received: by 2002:a1c:ed17:: with SMTP id l23mr18967788wmh.73.1593457247031; Mon, 29 Jun 2020 12:00:47 -0700 (PDT) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id x14sm755540wrt.60.2020.06.29.12.00.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jun 2020 12:00:45 -0700 (PDT) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 55D001FF7E; Mon, 29 Jun 2020 20:00:44 +0100 (BST) References: <158947246472.30762.752698283456022174.malonedeb@chaenomeles.canonical.com> <159344662125.1630.9077511492884316123.malone@chaenomeles.canonical.com> User-agent: mu4e 1.5.3; emacs 28.0.50 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: Bug 1878645 <1878645@bugs.launchpad.net> Subject: Re: [Bug 1878645] Re: null-ptr dereference in tcg_handle_interrupt In-reply-to: <159344662125.1630.9077511492884316123.malone@chaenomeles.canonical.com> Date: Mon, 29 Jun 2020 20:00:44 +0100 Message-ID: <871rlxsnmr.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::331; envelope-from=alex.bennee@linaro.org; helo=mail-wm1-x331.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Alexander Bulekov <1878645@bugs.launchpad.net> writes: > I don't think this is a qtest-specific error:=20 > cat << EOF| qemu-system-i386 -M q35 -nographic -serial none -monitor stdio > o/4 0xcf8 0x8400f841 > o/4 0xcfc 0xaa215d6d > o/4 0x6d30 0x2ef8ffbe > o/1 0xb2 0x20 > EOF > > ... > Segmentation fault Both this and the qtest have the same problem of depending on current_cpu which is a TLS variable which will never be correct from the qtest or monitor context. There are only a few other cases. sun4m:cpu_halt_signal does: if (level && current_cpu) { cpu_interrupt(current_cpu, CPU_INTERRUPT_HALT); } pxa2xx:pxa2xx_pwrmode_write does a bare: /* Suspend */ cpu_interrupt(current_cpu, CPU_INTERRUPT_HALT); but given the context has a CPUARMState *env it could arguably use that to derive current_cpu but as it's only triggered by a system register write you can't actually trigger from a monitor/qtest command. I would suggest either: } else if (current_cpu) { cpu_interrupt(current_cpu, CPU_INTERRUPT_SMI); } or possibly: } else { cpu_interrupt(current_cpu ? current_cpu : first_cpu, CPU_INTERR= UPT_SMI); } if you really care about triggering a real IRQ from outside the CPU context. --=20 Alex Benn=C3=A9e 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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 7BD0AC433E0 for ; Mon, 29 Jun 2020 19:11:38 +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 5376E206E2 for ; Mon, 29 Jun 2020 19:11:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5376E206E2 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]:54412 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jpzBp-00047B-Hn for qemu-devel@archiver.kernel.org; Mon, 29 Jun 2020 15:11:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47766) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jpzB6-0003T2-Rf for qemu-devel@nongnu.org; Mon, 29 Jun 2020 15:10:52 -0400 Received: from indium.canonical.com ([91.189.90.7]:53818) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jpzB0-0008Lp-Mr for qemu-devel@nongnu.org; Mon, 29 Jun 2020 15:10:52 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1jpzAy-0002D8-NZ for ; Mon, 29 Jun 2020 19:10:44 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id A5E2A2E810C for ; Mon, 29 Jun 2020 19:10:44 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Mon, 29 Jun 2020 19:00:44 -0000 From: =?utf-8?q?Alex_Benn=C3=A9e?= <1878645@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=New; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: a1xndr ajbennee X-Launchpad-Bug-Reporter: Alexander Bulekov (a1xndr) X-Launchpad-Bug-Modifier: =?utf-8?q?Alex_Benn=C3=A9e_=28ajbennee=29?= References: <158947246472.30762.752698283456022174.malonedeb@chaenomeles.canonical.com> <159344662125.1630.9077511492884316123.malone@chaenomeles.canonical.com> Message-ID: <871rlxsnmr.fsf@linaro.org> Subject: Re: [Bug 1878645] Re: null-ptr dereference in tcg_handle_interrupt 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="1cbd0aa39df153c901321817f9b57cf3f232b507"; Instance="production-secrets-lazr.conf" X-Launchpad-Hash: 392c7484b35cea3c64d1e0d54997d28b47b68247 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 = 2020/06/29 06:50:40 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -58 X-Spam_score: -5.9 X-Spam_bar: ----- X-Spam_report: (-5.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=_AUTOLEARN 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 1878645 <1878645@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20200629190044.VLPU-ckWWkhu0O5XbxRfQELKx69ogC7knudsL_DbEHs@z> Alexander Bulekov <1878645@bugs.launchpad.net> writes: > I don't think this is a qtest-specific error: = > cat << EOF| qemu-system-i386 -M q35 -nographic -serial none -monitor stdio > o/4 0xcf8 0x8400f841 > o/4 0xcfc 0xaa215d6d > o/4 0x6d30 0x2ef8ffbe > o/1 0xb2 0x20 > EOF > > ... > Segmentation fault Both this and the qtest have the same problem of depending on current_cpu which is a TLS variable which will never be correct from the qtest or monitor context. There are only a few other cases. sun4m:cpu_halt_signal does: if (level && current_cpu) { cpu_interrupt(current_cpu, CPU_INTERRUPT_HALT); } pxa2xx:pxa2xx_pwrmode_write does a bare: /* Suspend */ cpu_interrupt(current_cpu, CPU_INTERRUPT_HALT); but given the context has a CPUARMState *env it could arguably use that to derive current_cpu but as it's only triggered by a system register write you can't actually trigger from a monitor/qtest command. I would suggest either: } else if (current_cpu) { cpu_interrupt(current_cpu, CPU_INTERRUPT_SMI); } or possibly: } else { cpu_interrupt(current_cpu ? current_cpu : first_cpu, CPU_INTERR= UPT_SMI); } if you really care about triggering a real IRQ from outside the CPU context. -- = 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/1878645 Title: null-ptr dereference in ich9_apm_ctrl_changed Status in QEMU: New Bug description: Hello, While fuzzing, I found an input which triggers a NULL pointer dereference= in tcg_handle_interrupt. It seems the culprint is a "cpu" pointer - maybe th= is bug is specific to QTest? =3D=3D23862=3D=3DERROR: AddressSanitizer: SEGV on unknown address 0x00000= 00000b4 (pc 0x55b9dc7c9dce bp 0x7ffc346a0900 sp 0x7ffc346a0880 T0) =3D=3D23862=3D=3DThe signal is caused by a READ memory access. =3D=3D23862=3D=3DHint: address points to the zero page. #0 0x55b9dc7c9dce in tcg_handle_interrupt /home/alxndr/Development/qe= mu/accel/tcg/tcg-all.c:57:21 #1 0x55b9dc904799 in cpu_interrupt /home/alxndr/Development/qemu/incl= ude/hw/core/cpu.h:872:5 #2 0x55b9dc9085e8 in ich9_apm_ctrl_changed /home/alxndr/Development/q= emu/hw/isa/lpc_ich9.c:442:13 #3 0x55b9dd19cdc8 in apm_ioport_writeb /home/alxndr/Development/qemu/= hw/isa/apm.c:50:13 #4 0x55b9dc73f8b4 in memory_region_write_accessor /home/alxndr/Develo= pment/qemu/memory.c:483:5 #5 0x55b9dc73f289 in access_with_adjusted_size /home/alxndr/Developme= nt/qemu/memory.c:544:18 #6 0x55b9dc73ddf5 in memory_region_dispatch_write /home/alxndr/Develo= pment/qemu/memory.c:1476:16 #7 0x55b9dc577bf3 in flatview_write_continue /home/alxndr/Development= /qemu/exec.c:3137:23 #8 0x55b9dc567ad8 in flatview_write /home/alxndr/Development/qemu/exe= c.c:3177:14 #9 0x55b9dc567608 in address_space_write /home/alxndr/Development/qem= u/exec.c:3268:18 #10 0x55b9dc723fe7 in cpu_outb /home/alxndr/Development/qemu/ioport.c= :60:5 #11 0x55b9dc72d3c0 in qtest_process_command /home/alxndr/Development/= qemu/qtest.c:392:13 #12 0x55b9dc72b186 in qtest_process_inbuf /home/alxndr/Development/qe= mu/qtest.c:710:9 #13 0x55b9dc72a8b3 in qtest_read /home/alxndr/Development/qemu/qtest.= c:722:5 #14 0x55b9ddc6e60b in qemu_chr_be_write_impl /home/alxndr/Development= /qemu/chardev/char.c:183:9 #15 0x55b9ddc6e75a in qemu_chr_be_write /home/alxndr/Development/qemu= /chardev/char.c:195:9 #16 0x55b9ddc77979 in fd_chr_read /home/alxndr/Development/qemu/chard= ev/char-fd.c:68:9 #17 0x55b9ddcff0e9 in qio_channel_fd_source_dispatch /home/alxndr/Dev= elopment/qemu/io/channel-watch.c:84:12 #18 0x7f7161eac897 in g_main_context_dispatch (/usr/lib/x86_64-linux-= gnu/libglib-2.0.so.0+0x4e897) #19 0x55b9ddebcb84 in glib_pollfds_poll /home/alxndr/Development/qemu= /util/main-loop.c:219:9 #20 0x55b9ddebb57d in os_host_main_loop_wait /home/alxndr/Development= /qemu/util/main-loop.c:242:5 #21 0x55b9ddebb176 in main_loop_wait /home/alxndr/Development/qemu/ut= il/main-loop.c:518:11 #22 0x55b9dcb4bd1d in qemu_main_loop /home/alxndr/Development/qemu/so= ftmmu/vl.c:1664:9 #23 0x55b9ddd1629c in main /home/alxndr/Development/qemu/softmmu/main= .c:49:5 #24 0x7f7160a5ce0a in __libc_start_main /build/glibc-GwnBeO/glibc-2.3= 0/csu/../csu/libc-start.c:308:16 #25 0x55b9dc49c819 in _start (/home/alxndr/Development/qemu/build/i38= 6-softmmu/qemu-system-i386+0xc9c819) = I can reproduce this in qemu 5.0 built with AddressSanitizer using these = qtest commands: cat << EOF | ./qemu-system-i386 \ -qtest stdio -nographic -monitor none -serial none \ -M pc-q35-5.0 outl 0xcf8 0x8400f841 outl 0xcfc 0xaa215d6d outl 0x6d30 0x2ef8ffbe outb 0xb2 0x20 EOF Please let me know if I can provide any further info. -Alex To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1878645/+subscriptions