sd-bus: don't blindly take incomplete ucred bits from AF_UNIX when constructing message

[elogind.git] / src / libsystemd / sd-bus / bus-message.c

diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index 9d6647b2c4cf58f777d820db465df92ad4716f4f..6889754a965f15da17261c94667fc296150c5da2 100644 (file)
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -420,10 +420,20 @@ int bus_message_from_header(
         m->n_fds = n_fds;
 
         if (ucred) {
-                m->creds.uid = ucred->uid;
                 m->creds.pid = ucred->pid;
+                m->creds.uid = ucred->uid;
                 m->creds.gid = ucred->gid;
-                m->creds.mask |= SD_BUS_CREDS_UID | SD_BUS_CREDS_PID | SD_BUS_CREDS_GID;
+
+                /* Due to namespace translations some data might be
+                 * missing from this ucred record. */
+                if (m->creds.pid > 0)
+                        m->creds.mask |= SD_BUS_CREDS_PID;
+
+                if (m->creds.uid != (uid_t) -1)
+                        m->creds.mask |= SD_BUS_CREDS_UID;
+
+                if (m->creds.gid != (gid_t) -1)
+                        m->creds.mask |= SD_BUS_CREDS_GID;
         }
 
         if (label) {