Re: [PATCH net] dccp/tcp: fix routing redirect race

From: Jonathan Maxwell
Date: Wed Mar 08 2017 - 22:43:33 EST

Sorry let me resend in plain text mode.

On Thu, Mar 9, 2017 at 1:10 PM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:
> On Thu, 2017-03-09 at 12:15 +1100, Jon Maxwell wrote:
>> We have seen a few incidents lately where a dst_enty has been freed
>> with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
>> dst_entry. If the conditions/timings are right a crash then ensues when the
>> freed dst_entry is referenced later on. A Common crashing back trace is:
> Very nice catch !

Thanks Eric.

> Don't we have a similar issue for IPv6 ?

Good point.

We checked and as far as we can tell IPv6 does not invalidate the route.
So it should be safer.