From patchwork Wed Jan 25 03:09:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Sandeen X-Patchwork-Id: 9536339 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 30BB16046A for ; Wed, 25 Jan 2017 03:09:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 249B526E76 for ; Wed, 25 Jan 2017 03:09:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 181FF27BA5; Wed, 25 Jan 2017 03:09:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 88FB826E76 for ; Wed, 25 Jan 2017 03:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751181AbdAYDJD (ORCPT ); Tue, 24 Jan 2017 22:09:03 -0500 Received: from sandeen.net ([63.231.237.45]:42226 "EHLO sandeen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137AbdAYDJD (ORCPT ); Tue, 24 Jan 2017 22:09:03 -0500 Received: from [10.0.0.4] (liberator [10.0.0.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by sandeen.net (Postfix) with ESMTPSA id 17D627895; Tue, 24 Jan 2017 21:07:57 -0600 (CST) Subject: [PATCH v8 1/5] xfs_db: sanitize agcount on load To: "Darrick J. Wong" , sandeen@redhat.com References: <148494391629.5256.3328772079712970611.stgit@birch.djwong.org> <148494392247.5256.10692618169002348643.stgit@birch.djwong.org> <20170123213108.GD31202@birch.djwong.org> <6ad3798a-c3f5-fd8f-ab05-62c0f878290c@sandeen.net> Cc: linux-xfs@vger.kernel.org From: Eric Sandeen Message-ID: <17bbf8d4-39f7-a542-6c9d-3cd96e865ddf@sandeen.net> Date: Tue, 24 Jan 2017 21:09:01 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <6ad3798a-c3f5-fd8f-ab05-62c0f878290c@sandeen.net> Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Before we get into libxfs_initialize_perag and try to blindly allocate a perag struct for every (possibly corrupted number of) AGs, see if we can read the last one. If not, assume it's corrupt, and load only the first AG. Do this only for an arbitrarily high-ish agcount, so that normal-ish geometry on a possibly truncated file or device will still do its best to make all readable AGs available. Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong --- v7: blow it all up v8: use bare libxfs_readbuf so verifiers don't matter, "ours goes to 1 million!" -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/libxfs/init.c b/libxfs/init.c index a08575a..a14aa17 100644 --- a/libxfs/init.c +++ b/libxfs/init.c @@ -817,6 +817,29 @@ libxfs_mount( return NULL; } + /* + * libxfs_initialize_perag will allocate a perag structure for each ag. + * If agcount is corrupted and insanely high, this will OOM the box. + * If the agount seems (arbitrarily) high, try to read what would be + * the last AG, and if that fails for a relatively high agcount, just + * read the first one and let the user know to check the geometry. + */ + if (sbp->sb_agcount > 1000000) { + bp = libxfs_readbuf(mp->m_dev, + XFS_AG_DADDR(mp, sbp->sb_agcount - 1, 0), 1, + !(flags & LIBXFS_MOUNT_DEBUGGER), NULL); + if (bp->b_error) { + fprintf(stderr, _("%s: read of AG %d failed\n"), + progname, sbp->sb_agcount); + if (!(flags & LIBXFS_MOUNT_DEBUGGER)) + return NULL; + fprintf(stderr, _("%s: limiting reads to AG 0\n"), + progname); + sbp->sb_agcount = 1; + } + libxfs_putbuf(bp); + } + error = libxfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi); if (error) { fprintf(stderr, _("%s: perag init failed\n"),