diff options
| author | Cong Wang <xiyou.wangcong@gmail.com> | 2025-04-17 11:47:31 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-23 17:16:50 -0700 |
| commit | 6ccbda44e2cc3d26fd22af54c650d6d5d801addf (patch) | |
| tree | 99bbfe170a36b3f6fddeb6479fcad59fdc8a4d65 /net | |
| parent | 3df275ef0a6ae181e8428a6589ef5d5231e58b5c (diff) | |
net_sched: hfsc: Fix a potential UAF in hfsc_dequeue() too
Similarly to the previous patch, we need to safe guard hfsc_dequeue()
too. But for this one, we don't have a reliable reproducer.
Fixes: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250417184732.943057-3-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/sch_hfsc.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index b368ac0595d5..6c8ef826cec0 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1641,10 +1641,16 @@ hfsc_dequeue(struct Qdisc *sch) if (cl->qdisc->q.qlen != 0) { /* update ed */ next_len = qdisc_peek_len(cl->qdisc); - if (realtime) - update_ed(cl, next_len); - else - update_d(cl, next_len); + /* Check queue length again since some qdisc implementations + * (e.g., netem/codel) might empty the queue during the peek + * operation. + */ + if (cl->qdisc->q.qlen != 0) { + if (realtime) + update_ed(cl, next_len); + else + update_d(cl, next_len); + } } else { /* the class becomes passive */ eltree_remove(cl); |