From: Hangyu Hua hbh25y@gmail.com

stable inclusion from stable-v6.6.35 commit 54c2c171c11a798fe887b3ff72922aa9d1411c1e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6R4J CVE: CVE-2024-36978

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ 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@gmail.com Acked-by: Cong Wang cong.wang@bytedance.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/sched/sch_multiq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c index 75c9c860182b..0d6649d937c9 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;