[src/trunk]: src/sys/netinet tcp(4): Bail early on sendoob if not connected.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b6f8486f7ede
branches:  trunk
changeset: 368200:b6f8486f7ede
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Tue Jun 28 01:44:19 2022 +0000

description:
tcp(4): Bail early on sendoob if not connected.

XXX Not sure if testing tp->t_template is the right way to discern
this -- I just reached for it because the downstream crash is a panic
on tp->t_template == NULL in tcp_output.

XXX In principle this could try connecting to the address, except
it's not passed down from the logic in uipc_socket.c to tcp_sendoob.

Reported-by: syzbot+a01f4cfec72790855ce2%syzkaller.appspotmail.com@localhost

diffstat:

 sys/netinet/tcp_usrreq.c |  14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)

diffs (35 lines):

diff -r 0bb27909f69f -r b6f8486f7ede sys/netinet/tcp_usrreq.c
--- a/sys/netinet/tcp_usrreq.c  Tue Jun 28 00:13:48 2022 +0000
+++ b/sys/netinet/tcp_usrreq.c  Tue Jun 28 01:44:19 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tcp_usrreq.c,v 1.230 2021/08/04 08:47:10 christos Exp $        */
+/*     $NetBSD: tcp_usrreq.c,v 1.231 2022/06/28 01:44:19 riastradh Exp $       */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -99,7 +99,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_usrreq.c,v 1.230 2021/08/04 08:47:10 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_usrreq.c,v 1.231 2022/06/28 01:44:19 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -1158,6 +1158,16 @@
                m_freem(control);
                return error;
        }
+       if (tp->t_template == NULL) {
+               /*
+                * XXX FreeBSD appears to open the connection
+                * automagically in this case, but the socket address
+                * isn't passed through here so we can't do that.
+                */
+               m_freem(m);
+               m_freem(control);
+               return ENOTCONN;
+       }
 
        ostate = tcp_debug_capture(tp, PRU_SENDOOB);