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authorDarrick J. Wong <darrick.wong@oracle.com>2016-12-05 12:32:50 +1100
committerDave Chinner <david@fromorbit.com>2016-12-05 12:32:50 +1100
commitd2a047f31e86941fa896e0e3271536d50aba415e (patch)
tree0ff8117d63fcf7b839a3facd7f2ca307efdb60c0 /fs/xfs
parentf7a136aee3c1c3f7daf87197b3b3c361744a2812 (diff)
xfs: forbid AG btrees with level == 0
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>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c10
-rw-r--r--fs/xfs/libxfs/xfs_ialloc.c9
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