lkml.org 
[lkml]   [2018]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH -next] cred: conditionally declare groups-related functions
On Thu, Jun 21, 2018 at 4:33 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
>
> The groups-related functions declared in include/linux/cred.h are
> defined in kernel/groups.c, which is compiled only when
> CONFIG_MULTIUSER=y. Move all these function declarations under #ifdef
> CONFIG_MULTIUSER to help avoid accidental usage in contexts where
> CONFIG_MULTIUSER might be disabled.
>
> This patch also adds a fallback for groups_search(). Currently this
> function is only called from kernel/groups.c itself and
> keys/permissions.c, which depends on CONFIG_MULTIUSER. However, the
> audit subsystem (which does not depend on CONFIG_MULTIUSER) calls this
> function in -next, so the fallback will be needed to avoid compilation
> errors or ugly workarounds.
>
> See also:
> https://lkml.org/lkml/2018/6/20/670
> https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git/commit/?h=next&id=af85d1772e31fed34165a1b3decef340cf4080c0
>
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> ---
> include/linux/cred.h | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/cred.h b/include/linux/cred.h
> index 631286535d0f..8917768453cc 100644
> --- a/include/linux/cred.h
> +++ b/include/linux/cred.h
> @@ -65,6 +65,12 @@ extern void groups_free(struct group_info *);
>
> extern int in_group_p(kgid_t);
> extern int in_egroup_p(kgid_t);
> +
> +extern int set_current_groups(struct group_info *);
> +extern void set_groups(struct cred *, struct group_info *);
> +extern int groups_search(const struct group_info *, kgid_t);
> +extern bool may_setgroups(void);
> +extern void groups_sort(struct group_info *);
> #else
> static inline void groups_free(struct group_info *group_info)
> {
> @@ -78,12 +84,12 @@ static inline int in_egroup_p(kgid_t grp)
> {
> return 1;
> }
> +
> +static inline int groups_search(const struct group_info *group_info, kgid_t grp)
> +{
> + return 0;

Is this the right fallback value? If CONFIG_MULTIUSER is disabled,
wouldn't we always want to indicate a group match? The in_group_p()
and in_egroup_p() dummy functions would seem to indicate that is the
correct behavior ...

> +}
> #endif
> -extern int set_current_groups(struct group_info *);
> -extern void set_groups(struct cred *, struct group_info *);
> -extern int groups_search(const struct group_info *, kgid_t);
> -extern bool may_setgroups(void);
> -extern void groups_sort(struct group_info *);
>
> /*
> * The security context of a task
> --
> 2.17.1
>


--
paul moore
www.paul-moore.com

\
 
 \ /
  Last update: 2018-06-21 23:17    [W:0.136 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site