diff -uNr qemu-2.12.0/slirp/misc.c qemu-2.12.0.mod/slirp/misc.c
--- qemu-2.12.0/slirp/misc.c	2018-04-24 19:30:47.000000000 +0300
+++ qemu-2.12.0.mod/slirp/misc.c	2018-06-25 14:11:33.273965457 +0300
@@ -146,7 +146,7 @@
 		dup2(s, 0);
 		dup2(s, 1);
 		dup2(s, 2);
-		for (s = getdtablesize() - 1; s >= 3; s--)
+		for (s = sysconf(_SC_OPEN_MAX) - 1; s >= 3; s--)
 		   close(s);
 
 		i = 0;