[PATCH -next v3] cred: conditionally declare groups-related functions
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/...
Reported-by: Randy Dunlap <rdunlap(a)infradead.org>
Tested-by: Randy Dunlap <rdunlap(a)infradead.org>
Signed-off-by: Ondrej Mosnacek <omosnace(a)redhat.com>
---
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(-)
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