diff --git a/usr.bin/sockstat/sockstat.c b/usr.bin/sockstat/sockstat.c
--- a/usr.bin/sockstat/sockstat.c
+++ b/usr.bin/sockstat/sockstat.c
@@ -1164,8 +1164,14 @@
 					f = RB_FIND(files_t, &ftree,
 					    &(struct file){ .xf_data =
 					    p->socket });
-					pos += xprintf("[%lu %d]",
-					    (u_long)f->xf_pid, f->xf_fd);
+					if (__predict_false(f == NULL))
+						/* Known to happen when a dgram
+						 * socket is open in the kernel,
+						 * gssd.sock for example */
+						pos += xprintf("??");
+					else
+						pos += xprintf("[%lu %d]",
+						    (u_long)f->xf_pid, f->xf_fd);
 				} else
 					pos += printaddr(&p->laddr->address);
 			}