Index: stable/12/lib/libjail/jail_getid.c
===================================================================
--- stable/12/lib/libjail/jail_getid.c	(revision 348537)
+++ stable/12/lib/libjail/jail_getid.c	(revision 348538)
@@ -1,115 +1,124 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2009 James Gritton.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/jail.h>
 #include <sys/uio.h>
 
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "jail.h"
 
 
 /*
  * Return the JID corresponding to a jail name.
  */
 int
 jail_getid(const char *name)
 {
 	char *ep;
 	int jid;
 	struct iovec jiov[4];
 
 	jid = strtoul(name, &ep, 10);
 	if (*name && !*ep) {
+		/*
+		 * jid == 0 is a special case; it will not appear in the
+		 * kernel's jail list, but naturally processes will be assigned
+		 * to it because it is prison 0.  Trivially return this one
+		 * without a trip to the kernel, because it always exists but
+		 * the lookup won't succeed.
+		 */
+		if (jid == 0)
+			return jid;
 		jiov[0].iov_base = __DECONST(char *, "jid");
 		jiov[0].iov_len = sizeof("jid");
 		jiov[1].iov_base = &jid;
 		jiov[1].iov_len = sizeof(jid);
 	} else {
 		jiov[0].iov_base = __DECONST(char *, "name");
 		jiov[0].iov_len = sizeof("name");
 		jiov[1].iov_len = strlen(name) + 1;
 		jiov[1].iov_base = alloca(jiov[1].iov_len);
 		strcpy(jiov[1].iov_base, name);
 	}
 	jiov[2].iov_base = __DECONST(char *, "errmsg");
 	jiov[2].iov_len = sizeof("errmsg");
 	jiov[3].iov_base = jail_errmsg;
 	jiov[3].iov_len = JAIL_ERRMSGLEN;
 	jail_errmsg[0] = 0;
 	jid = jail_get(jiov, 4, 0);
 	if (jid < 0 && !jail_errmsg[0])
 		snprintf(jail_errmsg, JAIL_ERRMSGLEN, "jail_get: %s",
 		    strerror(errno));
 	return jid;
 }
 
 /*
  * Return the name corresponding to a JID.
  */
 char *
 jail_getname(int jid)
 {
 	struct iovec jiov[6];
 	char *name;
 	char namebuf[MAXHOSTNAMELEN];
 
 	jiov[0].iov_base = __DECONST(char *, "jid");
 	jiov[0].iov_len = sizeof("jid");
 	jiov[1].iov_base = &jid;
 	jiov[1].iov_len = sizeof(jid);
 	jiov[2].iov_base = __DECONST(char *, "name");
 	jiov[2].iov_len = sizeof("name");
 	jiov[3].iov_base = namebuf;
 	jiov[3].iov_len = sizeof(namebuf);
 	jiov[4].iov_base = __DECONST(char *, "errmsg");
 	jiov[4].iov_len = sizeof("errmsg");
 	jiov[5].iov_base = jail_errmsg;
 	jiov[5].iov_len = JAIL_ERRMSGLEN;
 	jail_errmsg[0] = 0;
 	jid = jail_get(jiov, 6, 0);
 	if (jid < 0) {
 		if (!jail_errmsg[0])
 			snprintf(jail_errmsg, JAIL_ERRMSGLEN, "jail_get: %s",
 			    strerror(errno));
 		return NULL;
 	} else {
 		name = strdup(namebuf);
 		if (name == NULL)
 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
 	}
 	return name;
 }
Index: stable/12
===================================================================
--- stable/12	(revision 348537)
+++ stable/12	(revision 348538)

Property changes on: stable/12
___________________________________________________________________
Modified: svn:mergeinfo
## -0,0 +0,1 ##
   Merged /head:r348509