Re: [PATCH V2] xfs: fix string handling in get/set functions
From: Christoph Hellwig
Date: Wed Jun 06 2018 - 06:58:31 EST
> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 82f7c83c1dad..596e176c19a6 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -1828,13 +1828,13 @@ xfs_ioc_getlabel(
> /* Paranoia */
> BUILD_BUG_ON(sizeof(sbp->sb_fname) > FSLABEL_MAX);
>
> + /* 1 larger than sb_fname, so this ensures a trailing NUL char */
> + memset(label, 0, sizeof(label));
I don't get the comment. In fact I don't even get why we need any
comment here. This is a structure that gets copied to userspace,
and we zero the whole structure, as we should do by default for
anything that goes to userspace.
Otherwise this looks fine to me.