[IPV6]: Disallow RH0 by default.

A security issue is emerging.  Disallow Routing Header Type 0 by default
as we have been doing for IPv4.
Note: We allow RH2 by default because it is harmless.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 7552663aa125..452a82ce4796 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -172,6 +172,7 @@ struct ipv6_devconf ipv6_devconf __read_mostly = {
 #endif
 #endif
         .proxy_ndp              = 0,
+        .accept_source_route    = 0,    /* we do not accept RH0 by default. */
 };
 
 static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -203,6 +204,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 #endif
 #endif
         .proxy_ndp              = 0,
+        .accept_source_route    = 0,    /* we do not accept RH0 by default. */
 };
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@@ -3356,6 +3358,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
 #endif
 #endif
         array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
+        array[DEVCONF_ACCEPT_SOURCE_ROUTE] = cnf->accept_source_route;
 }
 
 static inline size_t inet6_if_nlmsg_size(void)
@@ -3884,6 +3887,14 @@ static struct addrconf_sysctl_table
                         .proc_handler   =       &proc_dointvec,
                 },
                 {
+                        .ctl_name       =       NET_IPV6_ACCEPT_SOURCE_ROUTE,
+                        .procname       =       "accept_source_route",
+                        .data           =       &ipv6_devconf.accept_source_route,
+                        .maxlen         =       sizeof(int),
+                        .mode           =       0644,
+                        .proc_handler   =       &proc_dointvec,
+                },
+                {
                         .ctl_name       =       0,      /* sentinel */
                 }
         },