4.18-stable review patch. If anyone has any objections, please let me know.
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From: David Ahern dsahern@gmail.com
[ Upstream commit 4ed591c8ab44e711e56b8e021ffaf4f407c045f5 ]
The intent of ip6_route_check_nh_onlink is to make sure the gateway given for an onlink route is not actually on a connected route for a different interface (e.g., 2001:db8:1::/64 is on dev eth1 and then an onlink route has a via 2001:db8:1::1 dev eth2). If the gateway lookup hits the default route then it most likely will be a different interface than the onlink route which is ok.
Update ip6_route_check_nh_onlink to disregard the device mismatch if the gateway lookup hits the default route. Turns out the existing onlink tests are passing because there is no default route or it is an unreachable default, so update the onlink tests to have a default route other than unreachable.
Fixes: fc1e64e1092f6 ("net/ipv6: Add support for onlink flag") Signed-off-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/route.c | 2 ++ tools/testing/selftests/net/fib-onlink-tests.sh | 14 +++++++------- 2 files changed, 9 insertions(+), 7 deletions(-)
--- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2792,6 +2792,8 @@ static int ip6_route_check_nh_onlink(str grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0); if (grt) { if (!grt->dst.error && + /* ignore match if it is the default route */ + grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) && (grt->rt6i_flags & flags || dev != grt->dst.dev)) { NL_SET_ERR_MSG(extack, "Nexthop has invalid gateway or device mismatch"); --- a/tools/testing/selftests/net/fib-onlink-tests.sh +++ b/tools/testing/selftests/net/fib-onlink-tests.sh @@ -167,8 +167,8 @@ setup() # add vrf table ip li add ${VRF} type vrf table ${VRF_TABLE} ip li set ${VRF} up - ip ro add table ${VRF_TABLE} unreachable default - ip -6 ro add table ${VRF_TABLE} unreachable default + ip ro add table ${VRF_TABLE} unreachable default metric 8192 + ip -6 ro add table ${VRF_TABLE} unreachable default metric 8192
# create test interfaces ip li add ${NETIFS[p1]} type veth peer name ${NETIFS[p2]} @@ -185,20 +185,20 @@ setup() for n in 1 3 5 7; do ip li set ${NETIFS[p${n}]} up ip addr add ${V4ADDRS[p${n}]}/24 dev ${NETIFS[p${n}]} - ip addr add ${V6ADDRS[p${n}]}/64 dev ${NETIFS[p${n}]} + ip addr add ${V6ADDRS[p${n}]}/64 dev ${NETIFS[p${n}]} nodad done
# move peer interfaces to namespace and add addresses for n in 2 4 6 8; do ip li set ${NETIFS[p${n}]} netns ${PEER_NS} up ip -netns ${PEER_NS} addr add ${V4ADDRS[p${n}]}/24 dev ${NETIFS[p${n}]} - ip -netns ${PEER_NS} addr add ${V6ADDRS[p${n}]}/64 dev ${NETIFS[p${n}]} + ip -netns ${PEER_NS} addr add ${V6ADDRS[p${n}]}/64 dev ${NETIFS[p${n}]} nodad done
- set +e + ip -6 ro add default via ${V6ADDRS[p3]/::[0-9]/::64} + ip -6 ro add table ${VRF_TABLE} default via ${V6ADDRS[p7]/::[0-9]/::64}
- # let DAD complete - assume default of 1 probe - sleep 1 + set +e }
cleanup()