From nobody Sat Apr 27 13:38:45 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1516402214211268.1623028131728; Fri, 19 Jan 2018 14:50:14 -0800 (PST) Received: from localhost ([::1]:50918 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecfUB-0000rN-E6 for importer@patchew.org; Fri, 19 Jan 2018 17:50:11 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36960) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecfRr-0007kj-6V for qemu-devel@nongnu.org; Fri, 19 Jan 2018 17:47:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecfRq-0000fl-0w for qemu-devel@nongnu.org; Fri, 19 Jan 2018 17:47:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42058) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ecfRj-0000OX-VO; Fri, 19 Jan 2018 17:47:40 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F080F85A04; Fri, 19 Jan 2018 22:47:38 +0000 (UTC) Received: from probe.bos.redhat.com (dhcp-17-231.bos.redhat.com [10.18.17.231]) by smtp.corp.redhat.com (Postfix) with ESMTP id BAE675C1B7; Fri, 19 Jan 2018 22:47:35 +0000 (UTC) From: John Snow To: qemu-block@nongnu.org Date: Fri, 19 Jan 2018 17:47:35 -0500 Message-Id: <20180119224735.12169-1-jsnow@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 19 Jan 2018 22:47:39 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4] file-posix: specify expected filetypes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, John Snow , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Adjust each caller of raw_open_common to specify if they are expecting host and character devices or not. Tighten expectations of file types upon open in the common code and refuse types that are not expected. This has two effects: (1) Character and block devices are now considered deprecated for the 'file' driver, which expects only S_IFREG, and (2) no file-posix driver (file, host_cdrom, or host_device) can open directories now. I don't think there's a legitimate reason to open directories as if they were files. This prevents QEMU from opening and attempting to probe a directory inode, which can break in exciting ways. One of those ways is lseek on ext4/xfs, which will return 0x7fffffffffffffff as the file size instead of EISDIR. This can coax QEMU into responding with a confusing "file too big" instead of "Hey, that's not a file". See: https://bugs.launchpad.net/qemu/+bug/1739304/ Signed-off-by: John Snow Reviewed-by: Eric Blake --- v4: fixing doc building bug, sorry :( block/file-posix.c | 37 +++++++++++++++++++++++++++++-------- qemu-doc.texi | 6 ++++++ 2 files changed, 35 insertions(+), 8 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 36ee89e940..61fac1d2a4 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -417,7 +417,8 @@ static QemuOptsList raw_runtime_opts =3D { }; =20 static int raw_open_common(BlockDriverState *bs, QDict *options, - int bdrv_flags, int open_flags, Error **errp) + int bdrv_flags, int open_flags, + bool device, Error **errp) { BDRVRawState *s =3D bs->opaque; QemuOpts *opts; @@ -556,10 +557,30 @@ static int raw_open_common(BlockDriverState *bs, QDic= t *options, error_setg_errno(errp, errno, "Could not stat file"); goto fail; } - if (S_ISREG(st.st_mode)) { - s->discard_zeroes =3D true; - s->has_fallocate =3D true; + + if (!device) { + if (S_ISBLK(st.st_mode)) { + warn_report("Opening a block device as file using 'file' " + "driver is deprecated"); + } else if (S_ISCHR(st.st_mode)) { + warn_report("Opening a character device as file using the 'fil= e' " + "driver is deprecated"); + } else if (!S_ISREG(st.st_mode)) { + error_setg(errp, "A regular file was expected by the 'file' dr= iver, " + "but something else was given"); + goto fail; + } else { + s->discard_zeroes =3D true; + s->has_fallocate =3D true; + } + } else { + if (!(S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) { + error_setg(errp, "host_device/host_cdrom driver expects either= " + "a character or block device"); + goto fail; + } } + if (S_ISBLK(st.st_mode)) { #ifdef BLKDISCARDZEROES unsigned int arg; @@ -611,7 +632,7 @@ static int raw_open(BlockDriverState *bs, QDict *option= s, int flags, BDRVRawState *s =3D bs->opaque; =20 s->type =3D FTYPE_FILE; - return raw_open_common(bs, options, flags, 0, errp); + return raw_open_common(bs, options, flags, 0, false, errp); } =20 typedef enum { @@ -2575,7 +2596,7 @@ hdev_open_Mac_error: =20 s->type =3D FTYPE_FILE; =20 - ret =3D raw_open_common(bs, options, flags, 0, &local_err); + ret =3D raw_open_common(bs, options, flags, 0, true, &local_err); if (ret < 0) { error_propagate(errp, local_err); #if defined(__APPLE__) && defined(__MACH__) @@ -2802,7 +2823,7 @@ static int cdrom_open(BlockDriverState *bs, QDict *op= tions, int flags, s->type =3D FTYPE_CD; =20 /* open will not fail even if no CD is inserted, so add O_NONBLOCK */ - return raw_open_common(bs, options, flags, O_NONBLOCK, errp); + return raw_open_common(bs, options, flags, O_NONBLOCK, true, errp); } =20 static int cdrom_probe_device(const char *filename) @@ -2915,7 +2936,7 @@ static int cdrom_open(BlockDriverState *bs, QDict *op= tions, int flags, =20 s->type =3D FTYPE_CD; =20 - ret =3D raw_open_common(bs, options, flags, 0, &local_err); + ret =3D raw_open_common(bs, options, flags, 0, true, &local_err); if (ret) { error_propagate(errp, local_err); return ret; diff --git a/qemu-doc.texi b/qemu-doc.texi index 3e9eb819a6..8c94dcf8a6 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -2708,6 +2708,12 @@ that can be specified with the ``-device'' parameter. The drive addr argument is replaced by the the addr argument that can be specified with the ``-device'' parameter. =20 +@subsection -drive file=3Djson:@{...@{'driver':'file'@}@} (since 2.12.0) + +The 'file' driver for drives is no longer appropriate for character or host +devices and will only accept regular files (S_IFREG). The correct driver +for these file types is 'host_cdrom' or 'host_device' as appropriate. + @subsection -net dump (since 2.10.0) =20 The ``--net dump'' argument is now replaced with the --=20 2.14.3