linux-kernel - [PATCH -next v2] cred: conditionally declare groups-related functions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 25 Jun 2018 08:55:32 +0200
From:   Ondrej Mosnacek <omosnace@...hat.com>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Randy Dunlap <rdunlap@...radead.org>,
        Stephen Rothwell <sfr@...b.auug.org.au>,
        Paul Moore <paul@...l-moore.com>,
        Eric Paris <eparis@...hat.com>, linux-kernel@...r.kernel.org,
        linux-next@...r.kernel.org, linux-audit@...hat.com,
        Ondrej Mosnacek <omosnace@...hat.com>
Subject: [PATCH -next v2] 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
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@...radead.org>
Signed-off-by: Ondrej Mosnacek <omosnace@...hat.com>
---
 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