On Sat, Apr 12, 2025 at 08:03:57PM +0000, Charalampos Mitrodimas wrote:
> 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
> strictly increasing, as required by the B-tree structure.
>
> 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>
> ---
> 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..6c748911e54619c3ceae9b81f55cf61da6735f01 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)
Does XFS support a directory with two names that hash to the same value?
--D
> + 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>
>
>
