From: Guillaume Nault gnault@redhat.com
[ Upstream commit 91ffd1bae1dafbb9e34b46813f5b058581d9144d ]
Ping sockets can't send packets when they're bound to a VRF master device and the output interface is set to a slave device.
For example, when net.ipv4.ping_group_range is properly set, so that ping6 can use ping sockets, the following kind of commands fails: $ ip vrf exec red ping6 fe80::854:e7ff:fe88:4bf1%eth1
What happens is that sk->sk_bound_dev_if is set to the VRF master device, but 'oif' is set to the real output device. Since both are set but different, ping_v6_sendmsg() sees their value as inconsistent and fails.
Fix this by allowing 'oif' to be a slave device of ->sk_bound_dev_if.
This fixes the following kselftest failure: $ ./fcnal-test.sh -t ipv6_ping [...] TEST: ping out, vrf device+address bind - ns-B IPv6 LLA [FAIL]
Reported-by: Mirsad Todorovac mirsad.todorovac@alu.unizg.hr Closes: https://lore.kernel.org/netdev/b6191f90-ffca-dbca-7d06-88a9788def9c@alu.uniz... Tested-by: Mirsad Todorovac mirsad.todorovac@alu.unizg.hr Fixes: 5e457896986e ("net: ipv6: Fix ping to link-local addresses.") Signed-off-by: Guillaume Nault gnault@redhat.com Reviewed-by: David Ahern dsahern@kernel.org Link: https://lore.kernel.org/r/6c8b53108816a8d0d5705ae37bdc5a8322b5e3d9.168615384... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/ping.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 98ac32b49d8c9..91f352427dca2 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -96,7 +96,8 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) addr_type = ipv6_addr_type(daddr); if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) || (addr_type & IPV6_ADDR_MAPPED) || - (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if)) + (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if && + l3mdev_master_ifindex_by_index(sock_net(sk), oif) != sk->sk_bound_dev_if)) return -EINVAL;
/* TODO: use ip6_datagram_send_ctl to get options from cmsg */