sched_ext: scx_dsq_move() should validate the task belongs to the right scheduler

scx_bpf_dsq_move[_vtime]() calls scx_dsq_move() to move task from a DSQ to
another. However, @p doesn't necessarily have to come form the containing
iteration and can thus be a task which belongs to another scx_sched. Verify
that @p is on the same scx_sched as the DSQ being iterated.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
This commit is contained in:
Tejun Heo 2026-03-06 07:58:03 -10:00
parent 245d09c594
commit bb4d9fd551

View File

@ -6718,8 +6718,8 @@ static const struct btf_kfunc_id_set scx_kfunc_set_enqueue_dispatch = {
static bool scx_dsq_move(struct bpf_iter_scx_dsq_kern *kit,
struct task_struct *p, u64 dsq_id, u64 enq_flags)
{
struct scx_sched *sch = scx_root;
struct scx_dispatch_q *src_dsq = kit->dsq, *dst_dsq;
struct scx_sched *sch = src_dsq->sched;
struct rq *this_rq, *src_rq, *locked_rq;
bool dispatched = false;
bool in_balance;
@ -6736,6 +6736,11 @@ static bool scx_dsq_move(struct bpf_iter_scx_dsq_kern *kit,
if (unlikely(READ_ONCE(scx_aborting)))
return false;
if (unlikely(!scx_task_on_sched(sch, p))) {
scx_error(sch, "scx_bpf_dsq_move[_vtime]() on %s[%d] but the task belongs to a different scheduler",
p->comm, p->pid);
}
/*
* Can be called from either ops.dispatch() locking this_rq() or any
* context where no rq lock is held. If latter, lock @p's task_rq which