From patchwork Thu Jan 13 23:35:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sakib Sajal X-Patchwork-Id: 2405 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB4C9C43217 for ; Thu, 13 Jan 2022 23:36:21 +0000 (UTC) Received: from mail1.wrs.com (mail1.wrs.com [147.11.3.146]) by mx.groups.io with SMTP id smtpd.web09.292.1642116981291723154 for ; Thu, 13 Jan 2022 15:36:21 -0800 Authentication-Results: mx.groups.io; dkim=missing; spf=permerror, err=parse error for token &{10 18 %{ir}.%{v}.%{d}.spf.has.pphosted.com}: invalid domain name (domain: windriver.com, ip: 147.11.3.146, mailfrom: sakib.sajal@windriver.com) Received: from mail.windriver.com (mail.wrs.com [147.11.1.11]) by mail1.wrs.com (8.15.2/8.15.2) with ESMTPS id 20DNaFRa003719 (version=TLSv1.1 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Thu, 13 Jan 2022 15:36:21 -0800 Received: from ala-exchng01.corp.ad.wrs.com (ala-exchng01.corp.ad.wrs.com [147.11.82.252]) by mail.windriver.com (8.15.2/8.15.2) with ESMTPS id 20DNa6vp003925 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 13 Jan 2022 15:36:15 -0800 (PST) Received: from ala-exchng01.corp.ad.wrs.com (147.11.82.252) by ala-exchng01.corp.ad.wrs.com (147.11.82.252) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.12; Thu, 13 Jan 2022 15:36:11 -0800 Received: from yow-lpggp3.wrs.com (128.224.137.13) by ala-exchng01.corp.ad.wrs.com (147.11.82.252) with Microsoft SMTP Server id 15.1.2242.12 via Frontend Transport; Thu, 13 Jan 2022 15:36:11 -0800 From: Sakib Sajal To: Subject: [hardknott][PATCH 8/8] qemu: CVE-2021-20196 Date: Thu, 13 Jan 2022 18:35:51 -0500 Message-ID: <20220113233551.36855-8-sakib.sajal@windriver.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220113233551.36855-1-sakib.sajal@windriver.com> References: <20220113233551.36855-1-sakib.sajal@windriver.com> MIME-Version: 1.0 X-MIME-Autoconverted: from 8bit to quoted-printable by mail1.wrs.com id 20DNaFRa003719 List-Id: X-Webhook-Received: from li982-79.members.linode.com [45.33.32.79] by aws-us-west-2-korg-lkml-1.web.codeaurora.org with HTTPS for ; Thu, 13 Jan 2022 23:36:21 -0000 X-Groupsio-URL: https://lists.openembedded.org/g/openembedded-core/message/160545 Signed-off-by: Sakib Sajal --- meta/recipes-devtools/qemu/qemu.inc | 2 + .../qemu/qemu/CVE-2021-20196_1.patch | 54 +++++++++++++++ .../qemu/qemu/CVE-2021-20196_2.patch | 67 +++++++++++++++++++ 3 files changed, 123 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc index 4a5379893c..3401fd7194 100644 --- a/meta/recipes-devtools/qemu/qemu.inc +++ b/meta/recipes-devtools/qemu/qemu.inc @@ -80,6 +80,8 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \ file://CVE-2021-3713.patch \ file://CVE-2021-3748.patch \ file://CVE-2021-3930.patch \ + file://CVE-2021-20196_1.patch \ + file://CVE-2021-20196_2.patch \ " UPSTREAM_CHECK_REGEX = "qemu-(?P\d+(\.\d+)+)\.tar" diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch new file mode 100644 index 0000000000..bc513277ac --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_1.patch @@ -0,0 +1,54 @@ +From e907ff3d4cb7fd20d402f45355059e67d0dc93e7 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= +Date: Wed, 24 Nov 2021 17:15:34 +0100 +Subject: [PATCH 11/12] hw/block/fdc: Extract blk_create_empty_drive() +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +We are going to re-use this code in the next commit, +so extract it as a new blk_create_empty_drive() function. + +Inspired-by: Hanna Reitz +Signed-off-by: Philippe Mathieu-Daudé +Message-id: 20211124161536.631563-2-philmd@redhat.com +Signed-off-by: John Snow + +Upstream-Status: Backport +CVE: CVE-2021-20196 + +Signed-off-by: Sakib Sajal +--- + hw/block/fdc.c | 9 +++++++-- + 1 file changed, 7 insertions(+), 2 deletions(-) + +diff --git a/hw/block/fdc.c b/hw/block/fdc.c +index 4c2c35e22..854b4f172 100644 +--- a/hw/block/fdc.c ++++ b/hw/block/fdc.c +@@ -61,6 +61,12 @@ + } while (0) + + ++/* Anonymous BlockBackend for empty drive */ ++static BlockBackend *blk_create_empty_drive(void) ++{ ++ return blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); ++} ++ + /********************************************************/ + /* qdev floppy bus */ + +@@ -543,8 +549,7 @@ static void floppy_drive_realize(DeviceState *qdev, Error **errp) + } + + if (!dev->conf.blk) { +- /* Anonymous BlockBackend for an empty drive */ +- dev->conf.blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); ++ dev->conf.blk = blk_create_empty_drive(); + ret = blk_attach_dev(dev->conf.blk, qdev); + assert(ret == 0); + +-- +2.31.1 + diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch new file mode 100644 index 0000000000..1e39ed81b1 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2021-20196_2.patch @@ -0,0 +1,67 @@ +From 1d48445a951fd5504190a38abeda70ea9372cf77 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= +Date: Wed, 24 Nov 2021 17:15:35 +0100 +Subject: [PATCH 12/12] hw/block/fdc: Kludge missing floppy drive to fix + CVE-2021-20196 +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Guest might select another drive on the bus by setting the +DRIVE_SEL bit of the DIGITAL OUTPUT REGISTER (DOR). +The current controller model doesn't expect a BlockBackend +to be NULL. A simple way to fix CVE-2021-20196 is to create +an empty BlockBackend when it is missing. All further +accesses will be safely handled, and the controller state +machines keep behaving correctly. + +Cc: qemu-stable@nongnu.org +Fixes: CVE-2021-20196 +Reported-by: Gaoning Pan (Ant Security Light-Year Lab) +Reviewed-by: Darren Kenny +Reviewed-by: Hanna Reitz +Signed-off-by: Philippe Mathieu-Daudé +Message-id: 20211124161536.631563-3-philmd@redhat.com +BugLink: https://bugs.launchpad.net/qemu/+bug/1912780 +Resolves: https://gitlab.com/qemu-project/qemu/-/issues/338 +Reviewed-by: Darren Kenny +Reviewed-by: Hanna Reitz +Signed-off-by: Philippe Mathieu-Daudé +Signed-off-by: John Snow + +Upstream-Status: Backport +CVE: CVE-2021-20196 + +Signed-off-by: Sakib Sajal +--- + hw/block/fdc.c | 14 +++++++++++++- + 1 file changed, 13 insertions(+), 1 deletion(-) + +diff --git a/hw/block/fdc.c b/hw/block/fdc.c +index 854b4f172..a736c4d14 100644 +--- a/hw/block/fdc.c ++++ b/hw/block/fdc.c +@@ -1365,7 +1365,19 @@ static FDrive *get_drv(FDCtrl *fdctrl, int unit) + + static FDrive *get_cur_drv(FDCtrl *fdctrl) + { +- return get_drv(fdctrl, fdctrl->cur_drv); ++ FDrive *cur_drv = get_drv(fdctrl, fdctrl->cur_drv); ++ ++ if (!cur_drv->blk) { ++ /* ++ * Kludge: empty drive line selected. Create an anonymous ++ * BlockBackend to avoid NULL deref with various BlockBackend ++ * API calls within this model (CVE-2021-20196). ++ * Due to the controller QOM model limitations, we don't ++ * attach the created to the controller device. ++ */ ++ cur_drv->blk = blk_create_empty_drive(); ++ } ++ return cur_drv; + } + + /* Status A register : 0x00 (read-only) */ +-- +2.31.1 +