diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2017-01-09 16:38:51 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-12 11:39:42 +0100 |
| commit | b85f32481d93a23488d208fca4558e84515dc0f4 (patch) | |
| tree | 37fc914d5e42c633c1ac82b1db1ebb8a61065f6d | |
| parent | 4081d4a79a95252486569b014b9a666ad5bfdbee (diff) | |
xfs: forbid AG btrees with level == 0
commit d2a047f31e86941fa896e0e3271536d50aba415e upstream.
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 <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/xfs/libxfs/xfs_alloc.c | 10 | ||||
| -rw-r--r-- | 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 effb64cf714f..5050056a0b06 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 c482b9716347..d45c03779dae 100644 --- a/fs/xfs/libxfs/xfs_ialloc.c +++ b/fs/xfs/libxfs/xfs_ialloc.c @@ -2510,8 +2510,15 @@ 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 |