From: mvs <mvs@openbsd.org>
Date: Thu, 11 Feb 2021 20:28:01 +0000 (+0000)
Subject: We link `ifp' to `if_list' before we perform if_attachsetup(). It is not
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=8afa9f3ec1885f5426744f9dd55c436b9aa5ad6a;p=openbsd

We link `ifp' to `if_list' before we perform if_attachsetup(). It is not
fully initialized because we initialize `if_groups' after linking. It's
not triggered because if_attach() and if_unit(9) are serialized by
kernel lock and `ifp' is often filled by nulls. Move `if_groups'
initialization to if_attach_common() to prevent this.

ok bluhm@ claudio@ deraadt@
---

diff --git a/sys/net/if.c b/sys/net/if.c
index e9c29506b4c..32e6cf05f9a 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.628 2021/02/10 14:41:53 bluhm Exp $	*/
+/*	$OpenBSD: if.c,v 1.629 2021/02/11 20:28:01 mvs Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -423,8 +423,6 @@ if_attachsetup(struct ifnet *ifp)
 
 	NET_ASSERT_LOCKED();
 
-	TAILQ_INIT(&ifp->if_groups);
-
 	if_addgroup(ifp, IFG_ALL);
 
 	if_attachdomain(ifp);
@@ -596,6 +594,7 @@ if_attach_common(struct ifnet *ifp)
 
 	TAILQ_INIT(&ifp->if_addrlist);
 	TAILQ_INIT(&ifp->if_maddrlist);
+	TAILQ_INIT(&ifp->if_groups);
 
 	if (!ISSET(ifp->if_xflags, IFXF_MPSAFE)) {
 		KASSERTMSG(ifp->if_qstart == NULL,