userns: Convert group_info values from gid_t to kgid_t.

As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values.   Unless user namespaces are used this change should
have no effect.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

2 files changed, 7 insertions, 3 deletions

diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
index 79717a40dab..204438cc914 100644
--- a/fs/nfsd/auth.c
+++ b/fs/nfsd/auth.c
@@ -1,6 +1,7 @@
 /* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
 
 #include <linux/sched.h>
+#include <linux/user_namespace.h>
 #include "nfsd.h"
 #include "auth.h"
 
@@ -56,8 +57,8 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
                         goto oom;
 
                 for (i = 0; i < rqgi->ngroups; i++) {
-                        if (!GROUP_AT(rqgi, i))
-                                GROUP_AT(gi, i) = exp->ex_anon_gid;
+                        if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i)))
+                                GROUP_AT(gi, i) = make_kgid(&init_user_ns, exp->ex_anon_gid);
                         else
                                 GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
                 }
diff --git a/fs/proc/array.c b/fs/proc/array.c
index f9bd395b347..36a0a9192ec 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -81,6 +81,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/ptrace.h>
 #include <linux/tracehook.h>
+#include <linux/user_namespace.h>
 
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -161,6 +162,7 @@ static inline const char *get_task_state(struct task_struct *tsk)
 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
                                 struct pid *pid, struct task_struct *p)
 {
+        struct user_namespace *user_ns = current_user_ns();
         struct group_info *group_info;
         int g;
         struct fdtable *fdt = NULL;
@@ -205,7 +207,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
         task_unlock(p);
 
         for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
-                seq_printf(m, "%d ", GROUP_AT(group_info, g));
+                seq_printf(m, "%d ",
+                           from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
         put_cred(cred);
 
         seq_putc(m, '\n');