From: "Jonathan T. Leighton" <jtleight@xxxxxxxx> [ Upstream commit ec5e3b0a1d41fbda0cc33a45bc9e54e91d9d12c7 ] This patch adds a check for the problematic case of an IPv4-mapped IPv6 source address and a destination address that is neither an IPv4-mapped IPv6 address nor in6addr_any, and returns an appropriate error. The check in done before returning from looking up the route. Signed-off-by: Jonathan T. Leighton <jtleight@xxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- net/ipv6/ip6_output.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index e27b8fdba5d2..2f495063e4cc 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1016,6 +1016,9 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, } } #endif + if (ipv6_addr_v4mapped(&fl6->saddr) && + !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) + return -EAFNOSUPPORT; return 0; -- 2.11.0