userns: Convert the audit loginuid to be a kuid

Always store audit loginuids in type kuid_t.

Print loginuids by converting them into uids in the appropriate user
namespace, and then printing the resulting uid.

Modify audit_get_loginuid to return a kuid_t.

Modify audit_set_loginuid to take a kuid_t.

Modify /proc/<pid>/loginuid on read to convert the loginuid into the
user namespace of the opener of the file.

Modify /proc/<pid>/loginud on write to convert the loginuid
rom the user namespace of the opener of the file.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <paul@paul-moore.com> ?
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 0b5b8a232b55..26fdfc092e35 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -149,7 +149,7 @@ struct audit_aux_data_execve {
 struct audit_aux_data_pids {
         struct audit_aux_data   d;
         pid_t                   target_pid[AUDIT_AUX_PIDS];
-        uid_t                   target_auid[AUDIT_AUX_PIDS];
+        kuid_t                  target_auid[AUDIT_AUX_PIDS];
         uid_t                   target_uid[AUDIT_AUX_PIDS];
         unsigned int            target_sessionid[AUDIT_AUX_PIDS];
         u32                     target_sid[AUDIT_AUX_PIDS];
@@ -214,7 +214,7 @@ struct audit_context {
         int                 arch;
 
         pid_t               target_pid;
-        uid_t               target_auid;
+        kuid_t              target_auid;
         uid_t               target_uid;
         unsigned int        target_sessionid;
         u32                 target_sid;
@@ -1176,7 +1176,7 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-                                 uid_t auid, uid_t uid, unsigned int sessionid,
+                                 kuid_t auid, uid_t uid, unsigned int sessionid,
                                  u32 sid, char *comm)
 {
         struct audit_buffer *ab;
@@ -1188,7 +1188,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
         if (!ab)
                 return rc;
 
-        audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
+        audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
+                         from_kuid(&init_user_ns, auid),
                          uid, sessionid);
         if (security_secid_to_secctx(sid, &ctx, &len)) {
                 audit_log_format(ab, " obj=(none)");
@@ -1630,7 +1631,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                   context->name_count,
                   context->ppid,
                   context->pid,
-                  tsk->loginuid,
+                  from_kuid(&init_user_ns, tsk->loginuid),
                   context->uid,
                   context->gid,
                   context->euid, context->suid, context->fsuid,
@@ -2291,14 +2292,14 @@ static atomic_t session_id = ATOMIC_INIT(0);
  *
  * Called (set) from fs/proc/base.c::proc_loginuid_write().
  */
-int audit_set_loginuid(uid_t loginuid)
+int audit_set_loginuid(kuid_t loginuid)
 {
         struct task_struct *task = current;
         struct audit_context *context = task->audit_context;
         unsigned int sessionid;
 
 #ifdef CONFIG_AUDIT_LOGINUID_IMMUTABLE
-        if (task->loginuid != -1)
+        if (uid_valid(task->loginuid))
                 return -EPERM;
 #else /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */
         if (!capable(CAP_AUDIT_CONTROL))
@@ -2315,7 +2316,8 @@ int audit_set_loginuid(uid_t loginuid)
                                 "old auid=%u new auid=%u"
                                 " old ses=%u new ses=%u",
                                 task->pid, task_uid(task),
-                                task->loginuid, loginuid,
+                                from_kuid(&init_user_ns, task->loginuid),
+                                from_kuid(&init_user_ns, loginuid),
                                 task->sessionid, sessionid);
                         audit_log_end(ab);
                 }
@@ -2543,7 +2545,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
         if (audit_pid && t->tgid == audit_pid) {
                 if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
                         audit_sig_pid = tsk->pid;
-                        if (tsk->loginuid != -1)
+                        if (uid_valid(tsk->loginuid))
                                 audit_sig_uid = tsk->loginuid;
                         else
                                 audit_sig_uid = uid;