systemd: fix uninitialized memory access in selinux

[elogind.git] / src / core / selinux-access.c

diff --git a/src/core/selinux-access.c b/src/core/selinux-access.c
index d9c3f9bcdaa4f31d78165a67684ef4f864b49dfd..08a4834575a3c8548e99e34340f0f5e38bc69073 100644 (file)
--- a/src/core/selinux-access.c
+++ b/src/core/selinux-access.c
@@ -59,6 +59,10 @@ static int bus_get_selinux_security_context(
                 DBusError *error) {
 
         _cleanup_dbus_message_unref_ DBusMessage *m = NULL, *reply = NULL;
+        DBusMessageIter iter, sub;
+        const char *bytes;
+        char *b;
+        int nbytes;
 
         m = dbus_message_new_method_call(
                         DBUS_SERVICE_DBUS,
@@ -85,12 +89,21 @@ static int bus_get_selinux_security_context(
         if (dbus_set_error_from_message(error, reply))
                 return -EIO;
 
-        if (!dbus_message_get_args(
-                            reply, error,
-                            DBUS_TYPE_STRING, scon,
-                            DBUS_TYPE_INVALID))
+        if (!dbus_message_iter_init(reply, &iter))
                 return -EIO;
 
+        if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY)
+                return -EIO;
+
+        dbus_message_iter_recurse(&iter, &sub);
+        dbus_message_iter_get_fixed_array(&sub, &bytes, &nbytes);
+
+        b = strndup(bytes, nbytes);
+        if (!b)
+                return -ENOMEM;
+
+        *scon = b;
+
         return 0;
 }
 
@@ -119,7 +132,7 @@ static int bus_get_audit_data(
         if (r < 0)
                 return r;
 
-        r = get_process_cmdline(pid, LINE_MAX, true, &audit->cmdline);
+        r = get_process_cmdline(pid, 0, true, &audit->cmdline);
         if (r < 0)
                 return r;
 
@@ -243,7 +256,7 @@ static int get_audit_data(
         const char *sender;
         int r, fd;
         struct ucred ucred;
-        socklen_t len;
+        socklen_t len = sizeof(ucred);
 
         sender = dbus_message_get_sender(message);
         if (sender)
@@ -265,7 +278,7 @@ static int get_audit_data(
         if (r < 0)
                 return r;
 
-        r = get_process_cmdline(ucred.pid, LINE_MAX, true, &audit->cmdline);
+        r = get_process_cmdline(ucred.pid, 0, true, &audit->cmdline);
         if (r < 0)
                 return r;
 
@@ -297,8 +310,8 @@ static int get_calling_context(
                 if (r >= 0)
                         return r;
 
-                log_debug("bus_get_selinux_security_context failed %m");
-                dbus_error_free(error);
+                log_error("bus_get_selinux_security_context failed: %m");
+                return r;
         }
 
         if (!dbus_connection_get_unix_fd(connection, &fd)) {
@@ -345,8 +358,6 @@ int selinux_access_check(
         if (r < 0)
                 return r;
 
-        log_debug("SELinux access check for path=%s permission=%s", strna(path), permission);
-
         audit.uid = audit.loginuid = (uid_t) -1;
         audit.gid = (gid_t) -1;
         audit.cmdline = NULL;