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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 9E64AC35247 for ; Tue, 4 Feb 2020 16:37:23 +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 6C72B2084E for ; Tue, 4 Feb 2020 16:37:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Xcm2FS7f" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C72B2084E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33190 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iz1CU-00068K-Hs for qemu-devel@archiver.kernel.org; Tue, 04 Feb 2020 11:37:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57653) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iz1Bp-0005Vh-WD for qemu-devel@nongnu.org; Tue, 04 Feb 2020 11:36:43 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iz1Bo-0007tY-Md for qemu-devel@nongnu.org; Tue, 04 Feb 2020 11:36:41 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:25084 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iz1Bo-0007q0-II for qemu-devel@nongnu.org; Tue, 04 Feb 2020 11:36:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580834199; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BPln3pKzQwpSG1lyHtwF7dMsNgH+pz1HCgnFaR89h3A=; b=Xcm2FS7fhI6L++suTtPVuIdSNAhNkA25FCmuxaXzvNgZtb88N2uDrRJ5PIcCfx46AmWO2a T+2h7rA8fdZ3ifyn0xXCI2PTfzpVoSorSG5bBEVTEUo3nP2QiiA3aKTlarxhUINQJQGfF+ 6yLE1fdBDNEziY4b9u9kfI5ATaoER08= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-334-M84-gTrRPraPH-cYah5Ukg-1; Tue, 04 Feb 2020 11:36:37 -0500 Received: by mail-qt1-f197.google.com with SMTP id o18so12698439qtt.19 for ; Tue, 04 Feb 2020 08:36:37 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=cDWQCQ/S1S7T7k29R7GPnGMp5ZqT3HG8zjx3wtcKAgw=; b=MUzrnPTIQxBZVB5etWbtFjGn5eWHQfUTCnFaAk/tsXcOJ+Rr4KUXOb6Gn1myzNvGd8 AxRpRX2pdv8gpSzHKLMrAl0SlhAxs5j5sm4TYcR/fTNVSCAw3wZAAJnuqnDe5fHYv12N BZr5OsEnNnHFtP3EJcr4YVOuERuj2QHjBu25KSBLVXEFCGTpWIS32kCwOf81VdtbPLgt J5LLzoaK/frAscTlOT05STQKtPbtb5lTiMFZAwppuM77ghc1aHKeiDBv51E2KavzIsqF DrgmxlHzzDDNI58i7tU5ObKLuZxe1iGEcZMlqvHj8unoOtxx0ZZ7fChLLuJbatGEzJhr a8Ug== X-Gm-Message-State: APjAAAVl/dSzRdzqSI0HERPmvX2OdJTkYIkmuUkrXqdSjH6D7Dqgm4qH 0xnHTtZZxlmWeZrVnLpmPdDvKeTqcsmsCy3NyANUwnXesGm/8sTThWrNsPD0qZGrtjunbiSFG25 fOlJwJfLaGgBwYSk= X-Received: by 2002:aed:3f70:: with SMTP id q45mr13415957qtf.310.1580834197071; Tue, 04 Feb 2020 08:36:37 -0800 (PST) X-Google-Smtp-Source: APXvYqzo6+jTPka252Lia598Nq8rnFjSLCA698myoTHhZoQRlN9zmQjzKhRVJp2VFKdUzpA+sfjaAA== X-Received: by 2002:aed:3f70:: with SMTP id q45mr13415934qtf.310.1580834196802; Tue, 04 Feb 2020 08:36:36 -0800 (PST) Received: from redhat.com (bzq-79-176-41-183.red.bezeqint.net. [79.176.41.183]) by smtp.gmail.com with ESMTPSA id n20sm11157669qkk.54.2020.02.04.08.36.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Feb 2020 08:36:36 -0800 (PST) Date: Tue, 4 Feb 2020 11:36:32 -0500 From: "Michael S. Tsirkin" To: Stefan Hajnoczi Subject: Re: [PATCH] virtio: clean up when virtio_queue_set_rings() fails Message-ID: <20200204113625-mutt-send-email-mst@kernel.org> References: <20200204151618.39296-1-stefanha@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200204151618.39296-1-stefanha@redhat.com> X-MC-Unique: M84-gTrRPraPH-cYah5Ukg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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: Alexander Bulekov , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Feb 04, 2020 at 03:16:18PM +0000, Stefan Hajnoczi wrote: > hw/virtio.c checks vq->vring.desc !=3D NULL to see if the vring has been > set up successfully. >=20 > When virtio_queue_set_rings() fails due to an invalid vring memory > address it must clear vq->vring.desc (and related fields) so we don't > treat this virtqueue as successfully initialized later on. >=20 > This bug was found by device fuzzing and can be triggered as follows: >=20 > $ qemu -M pc -device virtio-blk-pci,id=3Ddrv0,drive=3Ddrive0,addr=3D4.0= \ > -drive if=3Dnone,id=3Ddrive0,file=3Dnull-co://,format=3Draw,auto= -read-only=3Doff \ > -drive if=3Dnone,id=3Ddrive1,file=3Dnull-co://,file.read-zeroes= =3Don,format=3Draw \ > -display none \ > -qtest stdio > endianness > outl 0xcf8 0x80002020 > outl 0xcfc 0xe0000000 > outl 0xcf8 0x80002004 > outw 0xcfc 0x7 > write 0xe0000000 0x24 0x00ffffffabffffffabffffffabffffffabffffffabfffff= fabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffab5cffffff= abffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabffffffabf= fffffabffffffabffffffabffffffabffffffab0000000001 > inb 0x4 > writew 0xe000001c 0x1 > write 0xe0000014 0x1 0x0d >=20 > The following error message is produced: >=20 > qemu-system-x86_64: /home/stefanha/qemu/hw/virtio/virtio.c:286: vring_g= et_region_caches: Assertion `caches !=3D NULL' failed. >=20 > The backtrace looks like this: >=20 > #0 0x00007ffff5520625 in raise () at /lib64/libc.so.6 > #1 0x00007ffff55098d9 in abort () at /lib64/libc.so.6 > #2 0x00007ffff55097a9 in _nl_load_domain.cold () at /lib64/libc.so.6 > #3 0x00007ffff5518a66 in annobin_assert.c_end () at /lib64/libc.so.6 > #4 0x00005555559073da in vring_get_region_caches (vq=3D= ) at qemu/hw/virtio/virtio.c:286 > #5 vring_get_region_caches (vq=3D) at qemu/hw/virtio/vi= rtio.c:283 > #6 0x000055555590818d in vring_used_flags_set_bit (mask=3D1, vq=3D0x55= 55575ceea0) at qemu/hw/virtio/virtio.c:398 > #7 virtio_queue_split_set_notification (enable=3D0, vq=3D0x5555575ceea= 0) at qemu/hw/virtio/virtio.c:398 > #8 virtio_queue_set_notification (vq=3Dvq@entry=3D0x5555575ceea0, enab= le=3Denable@entry=3D0) at qemu/hw/virtio/virtio.c:451 > #9 0x0000555555908512 in virtio_queue_set_notification (vq=3Dvq@entry= =3D0x5555575ceea0, enable=3Denable@entry=3D0) at qemu/hw/virtio/virtio.c:44= 4 > #10 0x00005555558c697a in virtio_blk_handle_vq (s=3D0x5555575c57e0, vq= =3D0x5555575ceea0) at qemu/hw/block/virtio-blk.c:775 > #11 0x0000555555907836 in virtio_queue_notify_aio_vq (vq=3D0x5555575cee= a0) at qemu/hw/virtio/virtio.c:2244 > #12 0x0000555555cb5dd7 in aio_dispatch_handlers (ctx=3Dctx@entry=3D0x55= 555671a420) at util/aio-posix.c:429 > #13 0x0000555555cb67a8 in aio_dispatch (ctx=3D0x55555671a420) at util/a= io-posix.c:460 > #14 0x0000555555cb307e in aio_ctx_dispatch (source=3D, c= allback=3D, user_data=3D) at util/async.c:260 > #15 0x00007ffff7bbc510 in g_main_context_dispatch () at /lib64/libglib-= 2.0.so.0 > #16 0x0000555555cb5848 in glib_pollfds_poll () at util/main-loop.c:219 > #17 os_host_main_loop_wait (timeout=3D) at util/main-loo= p.c:242 > #18 main_loop_wait (nonblocking=3D) at util/main-loop.c:= 518 > #19 0x00005555559b20c9 in main_loop () at vl.c:1683 > #20 0x0000555555838115 in main (argc=3D, argv=3D, envp=3D) at vl.c:4441 >=20 > Reported-by: Alexander Bulekov > Signed-off-by: Stefan Hajnoczi Fixes: ??? > --- > hw/virtio/virtio.c | 5 +++++ > 1 file changed, 5 insertions(+) >=20 > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 2c5410e981..5d7f619a1e 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -2163,6 +2163,11 @@ void virtio_queue_set_rings(VirtIODevice *vdev, in= t n, hwaddr desc, > vdev->vq[n].vring.avail =3D avail; > vdev->vq[n].vring.used =3D used; > virtio_init_region_cache(vdev, n); > + if (vdev->broken) { > + vdev->vq[n].vring.desc =3D 0; > + vdev->vq[n].vring.avail =3D 0; > + vdev->vq[n].vring.used =3D 0; > + } > } > =20 > void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) > --=20 > 2.24.1