When using the escape sequence &~ the code path is client_loop() ->

client_simple_escape_filter() -> process_escapes() -> fork() and the pledge for
this path lacks the proc promise and therefore aborts the process.
The solution is to just add proc the promise to this specific pledge.

Reported by Gregoire Jadi gjadi ! omecha.info
Insight with tb@, OK jca@

diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index b1ed83f..a762773 100644 (file)
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.299 2017/05/31 09:15:42 deraadt Exp $ */
+/* $OpenBSD: clientloop.c,v 1.300 2017/06/23 07:24:48 mestre Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1246,7 +1246,7 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
 
        } else {
                debug("pledge: network");
-               if (pledge("stdio unix inet dns tty", NULL) == -1)
+               if (pledge("stdio unix inet dns proc tty", NULL) == -1)
                        fatal("%s pledge(): %s", __func__, strerror(errno));
        }