Re: [PATCH v2 1/4] fs/posix_acl: apply umask if superblock disables ACL support
From: J. Bruce Fields
Date: Tue Aug 20 2019 - 17:26:54 EST
What happened to these patches? All four make sense to me, for what
it's worth; feel free to add a
Reviewed-by: J. Bruce Fields <bfields@xxxxxxxxxx>
--b.
On Sat, Jul 13, 2019 at 06:11:57AM +0200, Max Kellermann wrote:
> The function posix_acl_create() applies the umask only if the inode
> has no ACL (= NULL) or if ACLs are not supported by the filesystem
> driver (= -EOPNOTSUPP).
>
> However, this happens only after after the IS_POSIXACL() check
> succeeeded. If the superblock doesn't enable ACL support, umask will
> never be applied. A filesystem which has no ACL support will of
> course not enable SB_POSIXACL, rendering the umask-applying code path
> unreachable.
>
> This fixes a bug which causes the umask to be ignored with O_TMPFILE
> on tmpfs:
>
> https://github.com/MusicPlayerDaemon/MPD/issues/558
> https://bugs.gentoo.org/show_bug.cgi?id=686142#c3
> https://bugzilla.kernel.org/show_bug.cgi?id=203625
>
> Signed-off-by: Max Kellermann <mk@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> fs/posix_acl.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 84ad1c90d535..4071c66f234a 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -589,9 +589,14 @@ posix_acl_create(struct inode *dir, umode_t *mode,
> *acl = NULL;
> *default_acl = NULL;
>
> - if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
> + if (S_ISLNK(*mode))
> return 0;
>
> + if (!IS_POSIXACL(dir)) {
> + *mode &= ~current_umask();
> + return 0;
> + }
> +
> p = get_acl(dir, ACL_TYPE_DEFAULT);
> if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
> *mode &= ~current_umask();
> --
> 2.20.1