This is a note to let you know that I've just added the patch titled net: sched: sch_multiq: fix possible OOB write in multiq_tune() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-sched-sch_multiq-fix-possible-oob-write-in-multi.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dc581f99399c1bc308df11c1f4981df1ae227a95 Author: Hangyu Hua <hbh25y@xxxxxxxxx> Date: Mon Jun 3 15:13:03 2024 +0800 net: sched: sch_multiq: fix possible OOB write in multiq_tune() [ Upstream commit affc18fdc694190ca7575b9a86632a73b9fe043d ] q->bands will be assigned to qopt->bands to execute subsequent code logic after kmalloc. So the old q->bands should not be used in kmalloc. Otherwise, an out-of-bounds write will occur. Fixes: c2999f7fb05b ("net: sched: multiq: don't call qdisc_put() while holding tree lock") Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx> Acked-by: Cong Wang <cong.wang@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c index 1c6dbcfa89b87..77fd7be3a9cd1 100644 --- a/net/sched/sch_multiq.c +++ b/net/sched/sch_multiq.c @@ -185,7 +185,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt, qopt->bands = qdisc_dev(sch)->real_num_tx_queues; - removed = kmalloc(sizeof(*removed) * (q->max_bands - q->bands), + removed = kmalloc(sizeof(*removed) * (q->max_bands - qopt->bands), GFP_KERNEL); if (!removed) return -ENOMEM;