Hi, When syslogd is reloading a modified config, it does a reexec on itself. For this it uses the original arguments of main(). The function loghost_parse() modifies the optarg memory it is operating on. To prevent that the exec arguments have been tampered, pass a copy of optarg to loghost_parse().
ok? bluhm Index: usr.sbin/syslogd/syslogd.c =================================================================== RCS file: /data/mirror/openbsd/cvs/src/usr.sbin/syslogd/syslogd.c,v retrieving revision 1.178 diff -u -p -r1.178 syslogd.c --- usr.sbin/syslogd/syslogd.c 25 Aug 2015 17:14:16 -0000 1.178 +++ usr.sbin/syslogd/syslogd.c 27 Aug 2015 13:33:52 -0000 @@ -346,6 +346,8 @@ main(int argc, char *argv[]) struct timeval to; const char *errstr; char *p; + char udparg[NI_MAXHOST+2+NI_MAXSERV]; + char tcparg[NI_MAXHOST+2+NI_MAXSERV]; int ch, i; int lockpipe[2] = { -1, -1}, pair[2], nullfd, fd; @@ -393,12 +395,14 @@ main(int argc, char *argv[]) path_ctlsock = optarg; break; case 'T': /* allow tcp and listen on address */ - if (loghost_parse(optarg, NULL, &listen_host, + strlcpy(tcparg, optarg, sizeof(tcparg)); + if (loghost_parse(tcparg, NULL, &listen_host, &listen_port) == -1) errx(1, "bad listen address: %s", optarg); break; case 'U': /* allow udp only from address */ - if (loghost_parse(optarg, NULL, &bind_host, &bind_port) + strlcpy(udparg, optarg, sizeof(udparg)); + if (loghost_parse(udparg, NULL, &bind_host, &bind_port) == -1) errx(1, "bad bind address: %s", optarg); break;