Re: [PATCH net] ipv6: fix prefix route expiry in modify_prefix_route()

[Qishuai Liu]

On Thu, Sep 24, 2026 at 10:18 AM Hangbin Liu <hangbin.liu@xxxxxxxxx> wrote:
>
> On Wed, Sep 23, 2026 at 01:20:48PM +0000, Qishuai Liu wrote:
> > modify_prefix_route() is given the lifetime in clock_t relative to now,
> > but fib6_set_expires() wants an absolute jiffies value. So when a
> > permanent address is changed to a finite valid_lft, the prefix route
> > ends up already expired and GC removes it.
>
> nit: Does GC really removes it? I see the expires is negative, but the time
> seems overflow and GC won't remove it.

Yes, it is removed once the fib6 GC runs, i.e. within gc_interval if
the GC timer is already armed by another expiring route, or right away
with "sysctl -w net.ipv6.route.flush=1".