Re: [PATCH net] net: sched: gred: fix 32-bit backlog wrap in gred_enqueue

On Thu, Aug 13, 2026 at 9:45 PM Jakub Kicinski <[email protected]> wrote:
>
> On Sun, 9 Aug 2026 05:56:01 -0400 Jamal Hadi Salim wrote:
> > > The gred check is the newer of the two: it came in with a3eb95f891d6,
> > > the commit in your Fixes tag, while the bfifo one goes back to the
> > > initial git import, so there is no useful Fixes: tag for it.
> > >
> > > bfifo also has more ways in than gred.  sch_red.c and sch_tbf.c install a
> > > bfifo child through fifo_create_dflt() -> fifo_set_limit(), passing
> > > ctl->limit and qopt->limit straight from userspace; tc_red_qopt.limit is
> > > likewise documented as bytes.  Since this is heading to stable, fixing
> > > gred alone leaves those paths unchanged.
> > >
> >
> > I should have paid closer attention instead of focussing on the bug report.
> > Since i already submitted, we can wait to see sashiko says - if
> > requires an update i can include the others; otherwise it will have to
> > be a followup patch.
>
> I _think_ the Medium severity issue Clashiko called pre-existing is
> in fact a corner case missed by the fix? Please shout if you disagree..
> https://netdev-ai.bots.linux.dev/sashiko/#/patchset/[email protected]

yes, it is. Sashiko (Clashiko?) a bit pushy. I will send a v2 because
i want to add plug and the fifo qdiscs since it is the same
bug/pattern.
Some of these things are ridiculuos tbh but they are bugs
nevertheless. I'm happy to note the bots are no longer finding serious
bugs.

cheers,
jamal


> pw-bot: cr