diff options
| author | Xiang Mei <xmei5@asu.edu> | 2025-07-17 16:01:28 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-07-22 11:48:34 +0200 |
| commit | cf074eca0065bc5142e6004ae236bb35a2687fdf (patch) | |
| tree | f549b848ed65c0b66898221fda5f300296f122dc | |
| parent | b03f15c0192b184078206760c839054ae6eb4eaa (diff) | |
net/sched: sch_qfq: Avoid triggering might_sleep in atomic context in qfq_delete_class
might_sleep could be trigger in the atomic context in qfq_delete_class.
qfq_destroy_class was moved into atomic context locked
by sch_tree_lock to avoid a race condition bug on
qfq_aggregate. However, might_sleep could be triggered by
qfq_destroy_class, which introduced sleeping in atomic context (path:
qfq_destroy_class->qdisc_put->__qdisc_destroy->lockdep_unregister_key
->might_sleep).
Considering the race is on the qfq_aggregate objects, keeping
qfq_rm_from_agg in the lock but moving the left part out can solve
this issue.
Fixes: 5e28d5a3f774 ("net/sched: sch_qfq: Fix race condition on qfq_aggregate")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/4a04e0cc-a64b-44e7-9213-2880ed641d77@sabinyo.mountain
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20250717230128.159766-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/sched/sch_qfq.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index f0eb70353744..2255355e51d3 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -536,9 +536,6 @@ destroy_class: static void qfq_destroy_class(struct Qdisc *sch, struct qfq_class *cl) { - struct qfq_sched *q = qdisc_priv(sch); - - qfq_rm_from_agg(q, cl); gen_kill_estimator(&cl->rate_est); qdisc_put(cl->qdisc); kfree(cl); @@ -559,10 +556,11 @@ static int qfq_delete_class(struct Qdisc *sch, unsigned long arg, qdisc_purge_queue(cl->qdisc); qdisc_class_hash_remove(&q->clhash, &cl->common); - qfq_destroy_class(sch, cl); + qfq_rm_from_agg(q, cl); sch_tree_unlock(sch); + qfq_destroy_class(sch, cl); return 0; } @@ -1503,6 +1501,7 @@ static void qfq_destroy_qdisc(struct Qdisc *sch) for (i = 0; i < q->clhash.hashsize; i++) { hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i], common.hnode) { + qfq_rm_from_agg(q, cl); qfq_destroy_class(sch, cl); } } |