diff options
| author | Jiayuan Chen <jiayuan.chen@linux.dev> | 2026-04-13 19:45:20 +0800 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-04-16 13:48:30 +0200 |
| commit | 104f082f5ed6d19c5d85ca905ccd4e4d01aef66e (patch) | |
| tree | 26dcbf0472ec884e9b8a53c597bb1086002190ff | |
| parent | 29c95185ba32b621fbc3800fb86e7dc3edf5c2be (diff) | |
selftests: fib_nexthops: test stale has_v4 on nexthop replace
Add test cases that exercise the scenario where an IPv6 nexthop is
replaced with an IPv4 nexthop while being part of a group. The group's
has_v4 flag must be updated so that subsequent IPv6 route additions are
properly rejected.
Two cases are covered:
1. Gateway nexthop replaced across families with an existing IPv6
route on the group (rejected by fib6_check_nh_list).
2. Blackhole nexthop replaced across families with no existing IPv6
route on the group (fib6_check_nh_list returns early) — this is
the path that triggers a NULL ptr deref without the kernel fix.
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260413114522.147784-2-jiayuan.chen@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rwxr-xr-x | tools/testing/selftests/net/fib_nexthops.sh | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh index 6eb7f95e70e1..ac868a731694 100755 --- a/tools/testing/selftests/net/fib_nexthops.sh +++ b/tools/testing/selftests/net/fib_nexthops.sh @@ -1209,6 +1209,28 @@ ipv6_fcnal_runtime() run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 124" log_test $? 0 "IPv6 route using a group after replacing v4 gateways" + # Replacing an IPv6 nexthop with an IPv4 nexthop should update has_v4 + # for all groups using it, preventing IPv6 routes from referencing the + # group after the replace. + run_cmd "$IP nexthop add id 89 via 2001:db8:91::2 dev veth1" + run_cmd "$IP nexthop add id 125 group 89" + run_cmd "$IP nexthop replace id 89 via 172.16.1.1 dev veth1" + run_cmd "$IP ro replace 2001:db8:101::1/128 nhid 125" + log_test $? 2 "IPv6 route can not use group after v6 nexthop replaced by v4" + + # Same scenario but with a blackhole nexthop: the group has no IPv6 + # routes yet when the replace happens, so fib6_check_nh_list returns + # early without checking. has_v4 must still be updated to block + # subsequent IPv6 route additions. + run_cmd "$IP nexthop flush >/dev/null 2>&1" + run_cmd "$IP -6 nexthop add id 90 blackhole" + run_cmd "$IP nexthop add id 125 group 90" + run_cmd "$IP nexthop replace id 90 blackhole" + run_cmd "$IP -6 ro add 2001:db8:101::1/128 nhid 125" + log_test $? 2 "IPv6 route reject v6 blackhole replaced by v4 blackhole" + run_cmd "ip netns exec $me ping -6 2001:db8:101::1 -c1 -w$PING_TIMEOUT" + log_test $? 2 "Ping unreachable after rejected route" + $IP nexthop flush >/dev/null 2>&1 # |