Re: [PATCH] vfs: reorder checks in may_create_in_sticky
From: Jan Kara
Date: Thu Jun 20 2024 - 08:47:29 EST
On Thu 20-06-24 14:03:59, Mateusz Guzik wrote:
> The routine is called for all directories on file creation and weirdly
> postpones the check if the dir is sticky to begin with. Instead it first
> checks fifos and regular files (in that order), while avoidably pulling
> globals.
>
> No functional changes.
>
> Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx>
Yeah, putting the sticky bit check first makes sense also logically. Feel
free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/namei.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 63d1fb06da6b..b1600060ecfb 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -1246,9 +1246,9 @@ static int may_create_in_sticky(struct mnt_idmap *idmap,
> umode_t dir_mode = nd->dir_mode;
> vfsuid_t dir_vfsuid = nd->dir_vfsuid;
>
> - if ((!sysctl_protected_fifos && S_ISFIFO(inode->i_mode)) ||
> - (!sysctl_protected_regular && S_ISREG(inode->i_mode)) ||
> - likely(!(dir_mode & S_ISVTX)) ||
> + if (likely(!(dir_mode & S_ISVTX)) ||
> + (S_ISREG(inode->i_mode) && !sysctl_protected_regular) ||
> + (S_ISFIFO(inode->i_mode) && !sysctl_protected_fifos) ||
> vfsuid_eq(i_uid_into_vfsuid(idmap, inode), dir_vfsuid) ||
> vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), current_fsuid()))
> return 0;
> --
> 2.43.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR