[PATCH net 0/2] Introduce CBS reset ops
From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: 2026-05-05 13:16:20
From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: 2026-05-05 13:16:20
QFQ uses qlen to check whether it should reset pointer q->in_serv_agg. When QFQ has a CBS child which has a netem child it is possible to create a scenario where QFQ's qlen goes to 0 but the computation makes it underflow. This then aggrevates a null pointer deref. Jamal Hadi Salim (1): net/sched: sch_cbs: Call qdisc_reset for child qdisc Victor Nogueira (1): selftests/tc-testing: Add QFQ/CBS qlen underflow test net/sched/sch_cbs.c | 12 +++++- .../tc-testing/tc-tests/infra/qdiscs.json | 41 +++++++++++++++++++ 2 files changed, 52 insertions(+), 1 deletion(-) -- 2.34.1