diff --git a/fs/ntfs/runlist.c b/fs/ntfs/runlist.c index 9eaadbc0ef47..00373e450ea7 100644 --- a/fs/ntfs/runlist.c +++ b/fs/ntfs/runlist.c @@ -772,6 +772,25 @@ struct runlist_element *ntfs_mapping_pairs_decompress(const struct ntfs_volume * return ERR_PTR(-EIO); } + /* + * An empty mapping-pairs array is valid only for a zero-length + * attribute. + */ + if (!*buf && + (vcn || + le64_to_cpu(attr->data.non_resident.highest_vcn) != + (u64)(vcn - 1) || + le64_to_cpu(attr->data.non_resident.allocated_size) || + le64_to_cpu(attr->data.non_resident.data_size) || + le64_to_cpu(attr->data.non_resident.initialized_size))) { + ntfs_error(vol->sb, "Invalid empty mapping pairs array."); + return ERR_PTR(-EIO); + } + if (!vcn && !*buf && old_runlist && old_runlist->rl) { + *new_rl_count = old_runlist->count; + return old_runlist->rl; + } + /* Current position in runlist array. */ rlpos = 0; /* Allocate first page and set current runlist size to one page. */