@@ -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;;
@@ -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
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> --- fs/xfs/libxfs/xfs_alloc.c | 10 +++++++--- fs/xfs/libxfs/xfs_ialloc.c | 9 ++++++++- 2 files changed, 15 insertions(+), 4 deletions(-) -- 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