Index: head/sys/contrib/ipfilter/netinet/mlfk_ipl.c
===================================================================
--- head/sys/contrib/ipfilter/netinet/mlfk_ipl.c
+++ head/sys/contrib/ipfilter/netinet/mlfk_ipl.c
@@ -84,23 +84,23 @@
 SYSCTL_DECL(_net_inet);
 #define SYSCTL_IPF(parent, nbr, name, access, ptr, val, descr) \
     SYSCTL_OID(parent, nbr, name, \
-        CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_NEEDGIANT | access, \
+        CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_MPSAFE | access, \
         ptr, val, sysctl_ipf_int, "I", descr)
 #define SYSCTL_DYN_IPF_NAT(parent, nbr, name, access,ptr, val, descr) \
     SYSCTL_ADD_OID(&ipf_clist, SYSCTL_STATIC_CHILDREN(parent), nbr, name, \
-        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_NEEDGIANT |access, \
+        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_MPSAFE |access, \
         ptr, val, sysctl_ipf_int_nat, "I", descr)
 #define SYSCTL_DYN_IPF_STATE(parent, nbr, name, access,ptr, val, descr) \
     SYSCTL_ADD_OID(&ipf_clist, SYSCTL_STATIC_CHILDREN(parent), nbr, name, \
-        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_NEEDGIANT | access, \
+        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_MPSAFE | access, \
         ptr, val, sysctl_ipf_int_state, "I", descr)
 #define SYSCTL_DYN_IPF_FRAG(parent, nbr, name, access,ptr, val, descr) \
     SYSCTL_ADD_OID(&ipf_clist, SYSCTL_STATIC_CHILDREN(parent), nbr, name, \
-        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_NEEDGIANT | access, \
+        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_MPSAFE | access, \
 	ptr, val, sysctl_ipf_int_frag, "I", descr)
 #define SYSCTL_DYN_IPF_AUTH(parent, nbr, name, access,ptr, val, descr) \
     SYSCTL_ADD_OID(&ipf_clist, SYSCTL_STATIC_CHILDREN(parent), nbr, name, \
-        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_NEEDGIANT | access, \
+        CTLFLAG_DYN | CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_MPSAFE | access, \
 	ptr, val, sysctl_ipf_int_auth, "I", descr)
 static struct sysctl_ctx_list ipf_clist;
 #define	CTLFLAG_OFF	0x00800000	/* IPFilter must be disabled */
@@ -343,13 +343,14 @@
 {
 	int error = 0;
 
+	WRITE_ENTER(&V_ipfmain.ipf_mutex);
 	if (arg1)
 		error = SYSCTL_OUT(req, arg1, sizeof(int));
 	else
 		error = SYSCTL_OUT(req, &arg2, sizeof(int));
 
 	if (error || !req->newptr)
-		return (error);
+		goto sysctl_error;
 
 	if (!arg1)
 		error = EPERM;
@@ -359,6 +360,9 @@
 		else
 			error = SYSCTL_IN(req, arg1, sizeof(int));
 	}
+
+sysctl_error:
+	RWLOCK_EXIT(&V_ipfmain.ipf_mutex);
 	return (error);
 }