Re: net: heap out-of-bounds in fib6_clean_node/rt6_fill_node/fib6_age/fib6_prune_clone

[Dmitry Vyukov]

On Tue, Mar 7, 2017 at 7:43 PM, David Ahern <dsa@xxxxxxxxxxxxxxxxxxx> wrote:
> On 3/7/17 11:13 AM, Dmitry Vyukov wrote:
>>> on this warning:
>>>
>>> /* dst.next really should not be set at this point */
>>> if (rt->dst.next && rt->dst.next->ops->family != AF_INET6) {
>>>         pr_warn("fib6_add: adding rt with bad next -- family %d dst
>>> flags %x\n",
>>>                 rt->dst.next->ops->family, rt->dst.next->flags);
>>>
>>>         WARN_ON(1);
>>> }
>>>
>>> You should have seen the pr_warn in the log preceding the WARN_ON dump.
>>
>> Right. They all have the same "IPv6: fib6_add: adding rt with bad next
>> -- family 2 dst flags 6"
>
> remove the previous changes and try the attached.


Doing this now.
FWIW I've also applied your last patch with missing "iter->dst.flags
&= ~DST_IN_FIB;" and restored the warning in rt6_rcu_free and it did
not fire (in a limited run). I only saw the "WARNING in fib6_add" that
I already reported.