From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:22166 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752614AbcLCBf1 (ORCPT ); Fri, 2 Dec 2016 20:35:27 -0500 Subject: [PATCH 01/55] xfs: forbid AG btrees with level == 0 From: "Darrick J. Wong" Date: Fri, 02 Dec 2016 17:35:21 -0800 Message-ID: <148072892114.12995.3258531215811110809.stgit@birch.djwong.org> In-Reply-To: <148072891404.12995.15510849192837089093.stgit@birch.djwong.org> References: <148072891404.12995.15510849192837089093.stgit@birch.djwong.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: david@fromorbit.com, darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org There is no such thing as a zero-level AG btree since even a single-node zero-records btree has one level. Btree cursor constructors read cur_nlevels straight from disk and then access things like cur_bufs[cur_nlevels - 1] which is /really/ bad if cur_nlevels is zero! Therefore, strengthen the verifiers to prevent this possibility. Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_alloc.c | 10 +++++++--- fs/xfs/libxfs/xfs_ialloc.c | 9 ++++++++- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index effb64c..5050056 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2455,12 +2455,15 @@ xfs_agf_verify( be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp))) return false; - if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS || + if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 || + be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 || + be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS || be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS) return false; if (xfs_sb_version_hasrmapbt(&mp->m_sb) && - be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS) + (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 || + be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)) return false; /* @@ -2477,7 +2480,8 @@ xfs_agf_verify( return false; if (xfs_sb_version_hasreflink(&mp->m_sb) && - be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS) + (be32_to_cpu(agf->agf_refcount_level) < 1 || + be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS)) return false; return true;; diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c index c507c1b..30967c8 100644 --- a/fs/xfs/libxfs/xfs_ialloc.c +++ b/fs/xfs/libxfs/xfs_ialloc.c @@ -2513,8 +2513,15 @@ xfs_agi_verify( if (!XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum))) return false; - if (be32_to_cpu(agi->agi_level) > XFS_BTREE_MAXLEVELS) + if (be32_to_cpu(agi->agi_level) < 1 || + be32_to_cpu(agi->agi_level) > XFS_BTREE_MAXLEVELS) return false; + + if (xfs_sb_version_hasfinobt(&mp->m_sb) && + (be32_to_cpu(agi->agi_free_level) < 1 || + be32_to_cpu(agi->agi_free_level) > XFS_BTREE_MAXLEVELS)) + return false; + /* * during growfs operations, the perag is not fully initialised, * so we can't use it for any useful checking. growfs ensures we can't