From: Jiayuan Chen <[email protected]> Add a regression test for a panic triggered when an IPv4 route references a loopback IPv6 nexthop object. Without the fix, this sequence causes a NULL pointer dereference in __mkroute_output() because nhc_pcpu_rth_output is not allocated for the nexthop.
./fib_nexthops.sh Tests passed: 249 Tests failed: 0 Tests skipped: 2 Signed-off-by: Jiayuan Chen <[email protected]> --- tools/testing/selftests/net/fib_nexthops.sh | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh index 21026b667667..6eb7f95e70e1 100755 --- a/tools/testing/selftests/net/fib_nexthops.sh +++ b/tools/testing/selftests/net/fib_nexthops.sh @@ -1672,6 +1672,17 @@ ipv4_withv6_fcnal() run_cmd "$IP ro replace 172.16.101.1/32 via inet6 2001:db8:50::1 dev veth1" log_test $? 2 "IPv4 route with invalid IPv6 gateway" + + # Test IPv4 route with loopback IPv6 nexthop + # Regression test: loopback IPv6 nexthop was misclassified as reject + # route, skipping nhc_pcpu_rth_output allocation, causing panic when + # an IPv4 route references it and triggers __mkroute_output(). + run_cmd "$IP -6 nexthop add id 20 dev lo" + run_cmd "$IP ro add 172.20.20.0/24 nhid 20" + run_cmd "ip netns exec $me ping -c1 -W1 172.20.20.1" + log_test $? 1 "IPv4 route with loopback IPv6 nexthop (no crash)" + run_cmd "$IP ro del 172.20.20.0/24" + run_cmd "$IP nexthop del id 20" } ipv4_fcnal_runtime() -- 2.43.0
