svn commit: r197089 - stable/8/sys/netinet

[Shteryana Shopova]

Author: syrinx
Date: Fri Sep 11 15:07:36 2009
New Revision: 197089
URL: http://svn.freebsd.org/changeset/base/197089

Log:
  MFC r196932:
  
  When joining a multicast group, the inp_lookup_mcast_ifp call
  does a KASSERT that the group address is multicast, so the
  check if this is indeed true and eventually return a EINVAL if not,
  should be done before calling inp_lookup_mcast_ifp. This fixes a kernel
  crash when calling setsockopt (sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,...)
  with invalid group address.
  
  Reviewed by:	bms
  Approved by:	re (kib)

Modified:
  stable/8/sys/netinet/in_mcast.c

Modified: stable/8/sys/netinet/in_mcast.c
==============================================================================
--- stable/8/sys/netinet/in_mcast.c	Fri Sep 11 13:46:28 2009	(r197088)
+++ stable/8/sys/netinet/in_mcast.c	Fri Sep 11 15:07:36 2009	(r197089)
@@ -1899,6 +1899,9 @@ inp_join_group(struct inpcb *inp, struct
 			ssa->sin.sin_addr = mreqs.imr_sourceaddr;
 		}
 
+		if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
+			return (EINVAL);
+
 		ifp = inp_lookup_mcast_ifp(inp, &gsa->sin,
 		    mreqs.imr_interface);
 		CTR3(KTR_IGMPV3, "%s: imr_interface = %s, ifp = %p",
@@ -1936,6 +1939,9 @@ inp_join_group(struct inpcb *inp, struct
 			ssa->sin.sin_port = 0;
 		}
 
+		if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
+			return (EINVAL);
+
 		if (gsr.gsr_interface == 0 || V_if_index < gsr.gsr_interface)
 			return (EADDRNOTAVAIL);
 		ifp = ifnet_byindex(gsr.gsr_interface);
@@ -1948,9 +1954,6 @@ inp_join_group(struct inpcb *inp, struct
 		break;
 	}
 
-	if (!IN_MULTICAST(ntohl(gsa->sin.sin_addr.s_addr)))
-		return (EINVAL);
-
 	if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
 		return (EADDRNOTAVAIL);