selinux/stable-4.20 PR 20181129

-----BEGIN PGP SIGNATURE-----
 
 iQJIBAABCAAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAlwAFUUUHHBhdWxAcGF1
 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXM7ThAAw1j+HSBNM4util2Ji5JZKjjThdVe
 ZS1Jji30H51lVl3PNOfIUd9Ep3jLVbQOQ40jFQ2B8LEjjITKQykHtp4p6raYAxbb
 yEJGeVikD+UZ0izHMj05uZRBNY5F09s6y1WGMz8EZ6NdSSQezW0CpBCvKN4FpyKQ
 LgHmW7oRccSBgs5IcW8bCX/aM1p+HsI8N508T8MbO3qDt4/0OU/6OM+NAE19WvYp
 HVrq/BfRgDoQSoz3XxW5bCa7r3GFtxYYtTUjVnqBiRcEk+u67JJ5iJMwiUos1kV3
 94iAedGB1cXL0+qgyyb7eaoemSWL2A8FqTwEOL0VoIvaGzW4HJmioIzYgOGd4ni6
 BzXHIfdDff3DDWZ+g/T0da6znDLJ+R6u9xETAXcQ+g15FZ0F1ZY+3lJGlQvYfIVY
 RGHlWB93NU/Y2vebeqaGDuQOTu8XXJfBBjlHNUi3NQbRZ0ITBduTGpwpyKA6Uuiz
 cqrNt7DECTPJzOAJNeZZ7Flhfto1KQvLnPacWzjv9S8Cj1cJn2uS97QPkEqYQVYe
 b5D2PprAXpP6hPq3+Roxe+tBL1G+9XjStNrL0xPLgbiQvGCcsoD0R1dEZAesyfLO
 ZQGBP+0O/lFyQwn8T3A9QKZRgZFcfVMyOGbQRCUs98XkH0gvbLyfBNzN72aEy0+I
 ADbhCoY7pfs1ZZs=
 =SyQy
 -----END PGP SIGNATURE-----

Merge tag 'selinux-pr-20181129' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux fix from Paul Moore:
 "One more SELinux fix for v4.20: add some missing netlink message to
  SELinux permission mappings. The netlink messages were added in v4.19,
  but unfortunately we didn't catch it then because the mechanism to
  catch these things was bypassed.

  In addition to adding the mappings, we're adding some comments to the
  code to hopefully prevent bypasses in the future"

* tag 'selinux-pr-20181129' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: add support for RTM_NEWCHAIN, RTM_DELCHAIN, and RTM_GETCHAIN

security/selinux/nlmsgtab.c

@@ -80,6 +80,9 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
 	{ RTM_NEWSTATS,		NETLINK_ROUTE_SOCKET__NLMSG_READ },
 	{ RTM_GETSTATS,		NETLINK_ROUTE_SOCKET__NLMSG_READ  },
 	{ RTM_NEWCACHEREPORT,	NETLINK_ROUTE_SOCKET__NLMSG_READ },
+	{ RTM_NEWCHAIN,		NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+	{ RTM_DELCHAIN,		NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+	{ RTM_GETCHAIN,		NETLINK_ROUTE_SOCKET__NLMSG_READ  },
 };
 
 static const struct nlmsg_perm nlmsg_tcpdiag_perms[] =
@@ -158,7 +161,11 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
 
 	switch (sclass) {
 	case SECCLASS_NETLINK_ROUTE_SOCKET:
-		/* RTM_MAX always point to RTM_SETxxxx, ie RTM_NEWxxx + 3 */
+		/* RTM_MAX always points to RTM_SETxxxx, ie RTM_NEWxxx + 3.
+		 * If the BUILD_BUG_ON() below fails you must update the
+		 * structures at the top of this file with the new mappings
+		 * before updating the BUILD_BUG_ON() macro!
+		 */
 		BUILD_BUG_ON(RTM_MAX != (RTM_NEWCHAIN + 3));
 		err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
 				 sizeof(nlmsg_route_perms));
@@ -170,6 +177,10 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
 		break;
 
 	case SECCLASS_NETLINK_XFRM_SOCKET:
+		/* If the BUILD_BUG_ON() below fails you must update the
+		 * structures at the top of this file with the new mappings
+		 * before updating the BUILD_BUG_ON() macro!
+		 */
 		BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_MAPPING);
 		err = nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms,
 				 sizeof(nlmsg_xfrm_perms));