Index: sys/kern/kern_jail.c
===================================================================
--- sys/kern/kern_jail.c
+++ sys/kern/kern_jail.c
@@ -239,6 +239,19 @@
 static unsigned jail_max_af_ips = 255;
 #endif
 
+/*
+ * Copy the global osreldate and osrelease into prison0 early in kernel init so
+ * that they get inherited by jails that don't change the value at creation.
+ */
+static void
+prison0_init(void *dummy __unused)
+{
+
+	prison0.pr_osreldate = osreldate;
+	strlcpy(prison0.pr_osrelease, osrelease, sizeof(prison0.pr_osrelease));
+}
+SYSINIT(prison0init, SI_SUB_INTRINSIC, SI_ORDER_ANY, prison0_init, NULL);
+
 #ifdef INET
 static int
 qcmp_v4(const void *ip1, const void *ip2)
@@ -538,7 +551,7 @@
 	struct prison *pr, *deadpr, *mypr, *ppr, *tpr;
 	struct vnode *root;
 	char *domain, *errmsg, *host, *name, *namelc, *p, *path, *uuid;
-	char *g_path;
+	char *g_path, *osrelstr;
 #if defined(INET) || defined(INET6)
 	struct prison *tppr;
 	void *op;
@@ -548,7 +561,7 @@
 	int created, cuflags, descend, enforce, error, errmsg_len, errmsg_pos;
 	int gotchildmax, gotenforce, gothid, gotrsnum, gotslevel;
 	int fi, jid, jsys, len, level;
-	int childmax, rsnum, slevel;
+	int childmax, osreldt, rsnum, slevel;
 	int fullpath_disabled;
 #if defined(INET) || defined(INET6)
 	int ii, ij;
@@ -959,6 +972,45 @@
 		}
 	}
 
+	error = vfs_getopt(opts, "osrelease", (void **)&osrelstr, &len);
+	if (error == ENOENT)
+		osrelstr = NULL;
+	else if (error != 0)
+		goto done_free;
+	else {
+		if (flags & JAIL_UPDATE) {
+			error = EINVAL;
+			vfs_opterror(opts,
+			    "osrelease cannot be changed after creation");
+			goto done_errmsg;
+		}
+		if (len == 0 || len >= OSRELEASELEN) {
+			error = EINVAL;
+			vfs_opterror(opts,
+			    "osrelease string must be 1-31 bytes long");
+			goto done_errmsg;
+		}
+	}
+
+	error = vfs_copyopt(opts, "osreldate", &osreldt, sizeof(osreldt));
+	if (error == ENOENT)
+		osreldt = 0;
+	else if (error != 0)
+		goto done_free;
+	else {
+		if (flags & JAIL_UPDATE) {
+			error = EINVAL;
+			vfs_opterror(opts,
+			    "osreldate cannot be changed after creation");
+			goto done_errmsg;
+		}
+		if (osreldt == 0) {
+			error = EINVAL;
+			vfs_opterror(opts, "osreldate cannot be 0");
+			goto done_errmsg;
+		}
+	}
+
 	/*
 	 * Grab the allprison lock before letting modules check their
 	 * parameters.  Once we have it, do not let go so we'll have a
@@ -1285,6 +1337,12 @@
 		pr->pr_enforce_statfs = JAIL_DEFAULT_ENFORCE_STATFS;
 		pr->pr_devfs_rsnum = ppr->pr_devfs_rsnum;
 
+		pr->pr_osreldate = osreldt ? osreldt : ppr->pr_osreldate;
+		if (osrelstr == NULL)
+		    strcpy(pr->pr_osrelease, ppr->pr_osrelease);
+		else
+		    strcpy(pr->pr_osrelease, osrelstr);
+
 		LIST_INIT(&pr->pr_children);
 		mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF | MTX_DUPOK);
 
@@ -4309,6 +4367,10 @@
 SYSCTL_JAIL_PARAM_STRING(, path, CTLFLAG_RDTUN, MAXPATHLEN, "Jail root path");
 SYSCTL_JAIL_PARAM(, securelevel, CTLTYPE_INT | CTLFLAG_RW,
     "I", "Jail secure level");
+SYSCTL_JAIL_PARAM(, osreldate, CTLTYPE_INT | CTLFLAG_RD, "I", 
+    "Jail value for kern.osreldate");
+SYSCTL_JAIL_PARAM_STRING(, osrelease, CTLFLAG_RDTUN, MAXPATHLEN, 
+    "Jail value for kern.osrelease and uname -r");
 SYSCTL_JAIL_PARAM(, enforce_statfs, CTLTYPE_INT | CTLFLAG_RW,
     "I", "Jail cannot see all mounted file systems");
 SYSCTL_JAIL_PARAM(, devfs_ruleset, CTLTYPE_INT | CTLFLAG_RW,
Index: sys/kern/kern_mib.c
===================================================================
--- sys/kern/kern_mib.c
+++ sys/kern/kern_mib.c
@@ -90,9 +90,6 @@
 SYSCTL_STRING(_kern, OID_AUTO, ident, CTLFLAG_RD|CTLFLAG_MPSAFE,
     kern_ident, 0, "Kernel identifier");
 
-SYSCTL_STRING(_kern, KERN_OSRELEASE, osrelease, CTLFLAG_RD|CTLFLAG_MPSAFE|
-    CTLFLAG_CAPRD, osrelease, 0, "Operating system release");
-
 SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD|CTLFLAG_CAPRD,
     SYSCTL_NULL_INT_PTR, BSD, "Operating system revision");
 
@@ -105,13 +102,6 @@
 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE|
     CTLFLAG_CAPRD, ostype, 0, "Operating system type");
 
-/*
- * NOTICE: The *userland* release date is available in
- * /usr/include/osreldate.h
- */
-SYSCTL_INT(_kern, KERN_OSRELDATE, osreldate, CTLFLAG_RD|CTLFLAG_CAPRD,
-    &osreldate, 0, "Kernel release date");
-
 SYSCTL_INT(_kern, KERN_MAXPROC, maxproc, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
     &maxproc, 0, "Maximum number of processes");
 
@@ -429,6 +419,48 @@
     CTLTYPE_ULONG | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
     NULL, 0, sysctl_hostid, "LU", "Host ID");
 
+/*
+ * The osrelease string is copied from the global (osrelease in vers.c) into
+ * prison0 by a sysinit and is inherited by child jails if not changed at jail
+ * creation, so we always return the copy from the current prison data.
+ */
+static int
+sysctl_osrelease(SYSCTL_HANDLER_ARGS)
+{
+	struct prison *pr;
+
+	pr = req->td->td_ucred->cr_prison;
+	return (SYSCTL_OUT(req, pr->pr_osrelease, strlen(pr->pr_osrelease) + 1));
+
+}
+
+SYSCTL_PROC(_kern, KERN_OSRELEASE, osrelease,
+    CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
+    NULL, 0, sysctl_osrelease, "A", "Operating system release");
+
+/*
+ * The osreldate number is copied from the global (osreldate in vers.c) into
+ * prison0 by a sysinit and is inherited by child jails if not changed at jail
+ * creation, so we always return the value from the current prison data.
+ */
+static int
+sysctl_osreldate(SYSCTL_HANDLER_ARGS)
+{
+	struct prison *pr;
+
+	pr = req->td->td_ucred->cr_prison;
+	return (SYSCTL_OUT(req, &pr->pr_osreldate, sizeof(pr->pr_osreldate)));
+
+}
+
+/*
+ * NOTICE: The *userland* release date is available in
+ * /usr/include/osreldate.h
+ */
+SYSCTL_PROC(_kern, KERN_OSRELDATE, osreldate,
+    CTLTYPE_INT | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
+    NULL, 0, sysctl_osreldate, "I", "Kernel release date");
+
 SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel Features");
 
 #ifdef COMPAT_FREEBSD4
Index: sys/sys/jail.h
===================================================================
--- sys/sys/jail.h
+++ sys/sys/jail.h
@@ -134,6 +134,7 @@
 #include <sys/osd.h>
 
 #define	HOSTUUIDLEN	64
+#define	OSRELEASELEN	32
 
 struct racct;
 struct prison_racct;
@@ -184,6 +185,8 @@
 	char		 pr_hostname[MAXHOSTNAMELEN];	/* (p) jail hostname */
 	char		 pr_domainname[MAXHOSTNAMELEN];	/* (p) jail domainname */
 	char		 pr_hostuuid[HOSTUUIDLEN];	/* (p) jail hostuuid */
+	char		 pr_osrelease[OSRELEASELEN];	/* (c) kern.osrelease value */
+	int		 pr_osreldate;			/* (c) kern.osreldate value */
 };
 
 struct prison_racct {
Index: usr.sbin/jail/config.c
===================================================================
--- usr.sbin/jail/config.c
+++ usr.sbin/jail/config.c
@@ -117,6 +117,8 @@
     [KP_PERSIST] =		{"persist",		0},
     [KP_SECURELEVEL] =		{"securelevel",		0},
     [KP_VNET] =			{"vnet",		0},
+    [KP_OSRELDATE] =		{"osreldate",		PF_INT},
+    [KP_OSRELEASE] =		{"osrelease",		0},
 };
 
 /*
Index: usr.sbin/jail/jailp.h
===================================================================
--- usr.sbin/jail/jailp.h
+++ usr.sbin/jail/jailp.h
@@ -129,6 +129,8 @@
 	KP_PERSIST,
 	KP_SECURELEVEL,
 	KP_VNET,
+	KP_OSRELDATE,
+	KP_OSRELEASE,
 	IP_NPARAM
 };