The xfs_da3_node_verify() function checks the integrity of directory and attribute B-tree node blocks. However, it was missing a check to ensure that the hash values of the btree entries within the node are non-decreasing hash values (allowing equality). Add a loop to iterate through the btree entries and verify that each entry's hash value is greater than the previous one. If an out-of-order hash value is detected, return failure to indicate corruption. This addresses the "XXX: hash order check?" comment and improves corruption detection for DA node blocks. Signed-off-by: Charalampos Mitrodimas <charmitro@xxxxxxxxxx> --- Changes in v2: - Changed comparison from <= to < to allow equal hash values. - Updated commit message to clarify "non-decreasing" nature of hash values. - Link to v1: https://lore.kernel.org/r/20250412-xfs-hash-check-v1-1-fec1fef5d006@xxxxxxxxxx --- fs/xfs/libxfs/xfs_da_btree.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c index 17d9e6154f1978ce5a5cb82176eea4d6b9cd768d..7c42be30c3eb746e12b457ca6fce7c88ac191ba8 100644 --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -247,7 +247,16 @@ xfs_da3_node_verify( ichdr.count > mp->m_attr_geo->node_ents) return __this_address; - /* XXX: hash order check? */ + /* Check hash order */ + uint32_t prev_hash = be32_to_cpu(ichdr.btree[0].hashval); + + for (int i = 1; i < ichdr.count; i++) { + uint32_t curr_hash = be32_to_cpu(ichdr.btree[i].hashval); + + if (curr_hash < prev_hash) + return __this_address; + prev_hash = curr_hash; + } return NULL; } --- base-commit: ecd5d67ad602c2c12e8709762717112ef0958767 change-id: 20250412-xfs-hash-check-be7397881a2c Best regards, -- Charalampos Mitrodimas <charmitro@xxxxxxxxxx>
