example CLI:

vppctl abf policy add id 9001 acl 0 via 100.100.100.2 GigabitEthernet4/0/0
vppctl abf attach ip4 policy 9001 priority 1 GigabitEthernet3/0/0
vppctl ip route add 8.8.8.0/24 via 100.100.100.2 GigabitEthernet4/0/0

core:

received signal SIGSEGV, PC 0x7f51a1b60160, faulting address 0x7f61608d8814
#0 0x00007f51a0fde0db 0x7f51a0fde0db
#1 0x00007f51a0904890 0x7f51a0904890
#2 0x00007f51a1b60160 fib_urpf_list_lock + 0x10
#3 0x00007f51a1b5408f fib_entry_src_mk_lb + 0x1bf
#4 0x00007f51a1b54391 fib_entry_src_action_install + 0x131
#5 0x00007f51a1b51691 fib_entry_create + 0x71
#6 0x00007f51a1b486b8 fib_table_entry_update + 0x1c8
#7 0x00007f51a1b6398e fib_api_route_add_del + 0x7e
#8 0x00007f51a1879e3f vl_api_ip_route_add_del_t_handler + 0x21f
#9 0x00007f51a1f26d8c vl_msg_api_handler_with_vm_node + 0x8c
#10 0x00007f51a1f0b815 vl_mem_api_handle_msg_main + 0x45
#11 0x00007f51a1f1b38d 0x7f51a1f1b38d
#12 0x00007f51a0f92ea6 0x7f51a0f92ea6
#13 0x00007f51a04818bc 0x7f51a04818bc

reason:
the ABF policy creates a path-list that does not generate a uRPF list, the route shares the same path-list and expects it to have one.

fix:
add path list flags to the shared path-list DB key.