ipv6: Check IPV6_MULTICAST_LOOP option value.

Only 0 and 1 are valid for IPV6_MULTICAST_LOOP socket option,
and we should return an error of EINVAL otherwise, per RFC3493.

Based on patch from Shan Wei <shanwei@cn.fujitsu.com>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index ce794d6acb70..9a3697172d5e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -458,6 +458,8 @@ done:
         case IPV6_MULTICAST_LOOP:
                 if (optlen < sizeof(int))
                         goto e_inval;
+                if (val != valbool)
+                        goto e_inval;
                 np->mc_loop = valbool;
                 retv = 0;
                 break;