xfs: dabtree scrub needs to range-check level

Make sure scrub's dabtree iterator function checks that we're not
going deeper in the stack than our cursor permits.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c
index f1260b4..90527b0 100644 (file)
--- a/fs/xfs/scrub/dabtree.c
+++ b/fs/xfs/scrub/dabtree.c
@@ -574,6 +574,11 @@ xchk_da_btree(
                /* Drill another level deeper. */
                blkno = be32_to_cpu(key->before);
                level++;
+               if (level >= XFS_DA_NODE_MAXDEPTH) {
+                       /* Too deep! */
+                       xchk_da_set_corrupt(&ds, level - 1);
+                       break;
+               }
                ds.tree_level--;
                error = xchk_da_btree_block(&ds, level, blkno);
                if (error)