ipv6: protect protocols not handling ipv4 from v4 connection/bind attempts

Some ipv6 protocols cannot handle ipv4 addresses, so we must not allow
connecting and binding to them. sendmsg logic does already check msg->name
for this but must trust already connected sockets which could be set up
for connection to ipv4 address family.

Per-socket flag ipv6only is of no use here, as it is under users control
by setsockopt.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 4a9e4266a0c3..2d11c094296e 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -320,6 +320,9 @@ static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
                 if (addr_len < sizeof(*addr))
                         return -EINVAL;
 
+                if (addr->sin6_family != AF_INET6)
+                        return -EINVAL;
+
                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));