login: fix potential null pointer dereference

[elogind.git] / src / login / logind-core.c

diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index 67b03623acccb20dd24f11a0a9053403e94bc864..d5af8dcdc91701b53e1c2fe30ea703b6137c42d4 100644 (file)
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -31,6 +31,7 @@
 #include "bus-error.h"
 #include "udev-util.h"
 #include "logind.h"
+#include "terminal-util.h"
 
 int manager_add_device(Manager *m, const char *sysfs, bool master, Device **_device) {
         Device *d;
@@ -311,24 +312,41 @@ int manager_process_button_device(Manager *m, struct udev_device *d) {
 }
 
 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session) {
+        _cleanup_free_ char *session_name = NULL;
+        Session *s;
+        int r;
+
         assert(m);
         assert(session);
 
-        /* Without cgroups, we have no way to map from pid to
-           session.  */
-        return 0;
+        if (pid < 1)
+                return -EINVAL;
+
+        r = cg_pid_get_session(pid, &session_name);
+        if (r < 0)
+                return 0;
+
+        s = hashmap_get(m->sessions, session_name);
+        if (!s)
+                return 0;
+
+        *session = s;
+        return 1;
 }
 
 int manager_get_user_by_pid(Manager *m, pid_t pid, User **user) {
+        Session *s;
+        int r;
+
         assert(m);
         assert(user);
 
-        if (pid < 1)
-                return -EINVAL;
+        r = manager_get_session_by_pid (m, pid, &s);
+        if (r <= 0)
+                return r;
 
-        /* Without cgroups, we have no way to map from pid to
-           user.  */
-        return 0;
+        *user = s->user;
+        return 1;
 }
 
 int manager_get_idle_hint(Manager *m, dual_timestamp *t) {