On Mon, Mar 30, 2020 at 11:09:32AM +0200, Jan Kara wrote:
> There is an off-by-one error in dx_grow_tree() when checking whether we
> can add another level to the tree. Thus we can grow tree too much
> leading to possible crashes in the library or corrupted filesystem. Fix
> the bug.
Looks good, thanks
Reviewed-by: Lukas Czerner <lczerner@xxxxxxxxxx>
Don't we have basically the same off-by-one in
e2fsck/pass1.c handle_htree() ?
if ((root->indirect_levels > ext2_dir_htree_level(fs)) &&
fix_problem(ctx, PR_1_HTREE_DEPTH, pctx))
-Lukas
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> lib/ext2fs/link.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/ext2fs/link.c b/lib/ext2fs/link.c
> index 7b5bb022117c..469eea8cd06d 100644
> --- a/lib/ext2fs/link.c
> +++ b/lib/ext2fs/link.c
> @@ -473,7 +473,7 @@ static errcode_t dx_grow_tree(ext2_filsys fs, ext2_ino_t dir,
> ext2fs_le16_to_cpu(info->frames[i].head->limit))
> break;
> /* Need to grow tree depth? */
> - if (i < 0 && info->levels > ext2_dir_htree_level(fs))
> + if (i < 0 && info->levels >= ext2_dir_htree_level(fs))
> return EXT2_ET_DIR_NO_SPACE;
> lblk = size / fs->blocksize;
> size += fs->blocksize;
> --
> 2.16.4
>
