svn commit: r343647 - stable/12/sys/netinet6

[Hans Petter Selasky]

Author: hselasky
Date: Fri Feb  1 09:05:41 2019
New Revision: 343647
URL: https://svnweb.freebsd.org/changeset/base/343647

Log:
  MFC r343392:
  Fix duplicate acquiring of refcount when joining IPv6 multicast groups.
  This was observed by starting and stopping rpcbind(8) multiple times.
  
  PR:			233535
  Differential Revision:	https://reviews.freebsd.org/D18887
  Reviewed by:		bz (net)
  Tested by:		ae
  Sponsored by:		Mellanox Technologies

Modified:
  stable/12/sys/netinet6/in6_mcast.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/netinet6/in6_mcast.c
==============================================================================
--- stable/12/sys/netinet6/in6_mcast.c	Fri Feb  1 08:10:26 2019	(r343646)
+++ stable/12/sys/netinet6/in6_mcast.c	Fri Feb  1 09:05:41 2019	(r343647)
@@ -2178,7 +2178,10 @@ in6p_join_group(struct inpcb *inp, struct sockopt *sop
 			IN6_MULTI_UNLOCK();
 			goto out_im6o_free;
 		}
-		in6m_acquire(inm);
+		/*
+		 * NOTE: Refcount from in6_joingroup_locked()
+		 * is protecting membership.
+		 */
 		imo->im6o_membership[idx] = inm;
 	} else {
 		CTR1(KTR_MLD, "%s: merge inm state", __func__);