Re: [PATCH bpf-next] bpf: sched_ext: Mark ops argument container pointer fields as trusted

On Thu, Aug 20, 2026 at 06:16:48AM +0000, [email protected] wrote:
> >     bpf: sched_ext: Mark ops argument container pointer fields as trusted
> >
> >     Walking an unannotated pointer field of a trusted struct yields a bare
> >     PTR_TO_BTF_ID in non-sleepable programs, which kfuncs and helpers accept,
> >     but PTR_UNTRUSTED in sleepable programs, which they reject. This gets in the
> >     way of making ops.init_task() sleepable, which schedulers want for
> >     allocations. For example, passing args->cgroup into bpf_cgrp_storage_get()
> >     then fails verification and the only recourse is round-tripping through the
> >     cgroup ID with bpf_cgroup_from_id().
> >
> >     The pointer fields in the sched_ext ops argument containers are all pinned
> >     by the callers for the duration of the ops calls and are never NULL. Add
> >     them to the verifier's trusted-fields whitelist so that they are PTR_TRUSTED
> >     in both sleepable and non-sleepable programs.
> >
> >     Signed-off-by: Tejun Heo <[email protected]>
> 
> This looks like a bug fix for verification failures in sleepable programs.
> Should this include:
> 
>   Fixes: 8195136669661 ("sched_ext: Add cgroup support")

Nothing has been using it, so not strictly necessary but yeah I don't see
why not.

Thanks.

-- 
tejun