Created attachment 321 [details]
FIB error example

The error is due to overflow of the internal FIB counter "rsvd_tbl8s". After
this error occurs, it is impossible to add any rules even the FIB is empty.

To reproduce this error, simply insert two IP addresses of the following type
with the same next-hope parameter (this is important):
struct Network {
    uint32_t ip;
    uint16_t prefix;
};

/*
    first insertion with prefix less than 25 doesn't allocate tbl8 entry
    second insertion with prefix more than 24 will allocate tbl8 entry BUT only
when we pass the different next hope
*/
const struct Network state[] = {
    {0x3000000, 15}, {0x3000520, 29}
};

and delete them. Deleting the first rule will allocate tbl8 entry but
"rsvd_tbl8s" counter won't increment. Deleting the second rule will decrease
the counter "rsvd_tbl8s" and it will overflow.

The full reproduce program is in attachment.