svn commit: r313558 - stable/10/sys/netinet

[Eric van Gyzen]

Author: vangyzen
Date: Fri Feb 10 16:11:11 2017
New Revision: 313558
URL: https://svnweb.freebsd.org/changeset/base/313558

Log:
  MFC r313401
  
  Fix garbage IP addresses in UDP log_in_vain messages
  
  If multiple threads emit a UDP log_in_vain message concurrently,
  or indeed call inet_ntoa() for any other reason,
  the IP addresses could be garbage due to concurrent usage of a
  single string buffer inside inet_ntoa().  Use inet_ntoa_r() with
  two stack buffers instead.
  
  Relnotes:	yes
  Sponsored by:	Dell EMC

Modified:
  stable/10/sys/netinet/udp_usrreq.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/netinet/udp_usrreq.c
==============================================================================
--- stable/10/sys/netinet/udp_usrreq.c	Fri Feb 10 16:06:14 2017	(r313557)
+++ stable/10/sys/netinet/udp_usrreq.c	Fri Feb 10 16:11:11 2017	(r313558)
@@ -647,13 +647,13 @@ udp_input(struct mbuf *m, int off)
 		    INPLOOKUP_RLOCKPCB, ifp, m);
 	if (inp == NULL) {
 		if (udp_log_in_vain) {
-			char buf[4*sizeof "123"];
+			char src[INET_ADDRSTRLEN];
+			char dst[INET_ADDRSTRLEN];
 
-			strcpy(buf, inet_ntoa(ip->ip_dst));
 			log(LOG_INFO,
 			    "Connection attempt to UDP %s:%d from %s:%d\n",
-			    buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
-			    ntohs(uh->uh_sport));
+			    inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
+			    inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
 		}
 		UDPSTAT_INC(udps_noport);
 		if (m->m_flags & (M_BCAST | M_MCAST)) {