net_sched: hfsc: Fix a potential UAF in hfsc_dequeue() too

[ Upstream commit 6ccbda44e2cc3d26fd22af54c650d6d5d801addf ]

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: 1da177e4c3 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Cong Wang
2025-04-17 11:47:31 -07:00
committed by Greg Kroah-Hartman
parent 3aa852e360
commit 76c4c22c24

View File

@@ -1638,10 +1638,16 @@ 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);