[src/netbsd-9]: src/sys/netinet Pull up following revision(s) (requested by m...

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

details:   https://anonhg.NetBSD.org/src/rev/78a5b4a23f24
branches:  netbsd-9
changeset: 933020:78a5b4a23f24
user:      martin <martin%NetBSD.org@localhost>
date:      Mon May 18 18:59:39 2020 +0000

description:
Pull up following revision(s) (requested by maxv in ticket #915):

        sys/netinet/igmp.c: revision 1.70

igmp_sendpkt() expects ip_output() to set 'imo.imo_multicast_ttl' into
'ip->ip_ttl'; but ip_output() won't if the target is not a multicast
address, meaning that the uninitialized 'ip->ip_ttl' byte gets sent to
the network. This leaks one byte of kernel heap.

Fix this by filling 'ip->ip_ttl' with a TTL of one.

Found by KMSAN.

diffstat:

 sys/netinet/igmp.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (26 lines):

diff -r ceb11df877a4 -r 78a5b4a23f24 sys/netinet/igmp.c
--- a/sys/netinet/igmp.c        Mon May 18 18:57:31 2020 +0000
+++ b/sys/netinet/igmp.c        Mon May 18 18:59:39 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: igmp.c,v 1.69 2018/09/14 05:09:51 maxv Exp $   */
+/*     $NetBSD: igmp.c,v 1.69.4.1 2020/05/18 18:59:39 martin Exp $     */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -40,7 +40,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: igmp.c,v 1.69 2018/09/14 05:09:51 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: igmp.c,v 1.69.4.1 2020/05/18 18:59:39 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_mrouting.h"
@@ -613,6 +613,7 @@
        ip->ip_tos = 0;
        ip->ip_len = htons(sizeof(struct ip) + IGMP_MINLEN);
        ip->ip_off = htons(0);
+       ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
        ip->ip_p = IPPROTO_IGMP;
        ip->ip_src = zeroin_addr;
        ip->ip_dst = inm->inm_addr;