Re: [PATCH -next v3] cred: conditionally declare groups-related functions

[Paul Moore]

On Tue, Jun 26, 2018 at 7:04 AM Ondrej Mosnacek <omosnace@xxxxxxxxxx> 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
> security/keys/permissions.c, where the call is (by coincidence)
> optimized away in case CONFIG_MULTIUSER=n. 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@xxxxxxxxxxxxx>
> Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> ---
>
> Changes:
>     v2->v3: commit message corrections
>     v1->v2: change default return value of groups_search() to 1
>
>  include/linux/cred.h | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)

Merged, thanks guys.

> diff --git a/include/linux/cred.h b/include/linux/cred.h
> index 631286535d0f..7eed6101c791 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 groups_search(const struct group_info *, kgid_t);
> +
> +extern int set_current_groups(struct group_info *);
> +extern void set_groups(struct cred *, struct group_info *);
> +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 +84,11 @@ 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 1;
> +}
>  #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