mainline inclusion
from mainline-v6.5-rc2
commit 3e337087c3b5805fe0b8a46ba622a962880b5d64
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7N3MX
CVE: CVE-2023-3611

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3e337087c3b5805fe0b8a46ba622a962880b5d64

---------------------------

Lion says:
-------
In the QFQ scheduler a similar issue to CVE-2023-31436
persists.

Consider the following code in net/sched/sch_qfq.c:

static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
                struct sk_buff **to_free)
{
     unsigned int len = qdisc_pkt_len(skb), gso_segs;

    // ...

     if (unlikely(cl->agg->lmax < len)) {
         pr_debug("qfq: increasing maxpkt from %u to %u for class %u",
              cl->agg->lmax, len, cl->common.classid);
         err = qfq_change_agg(sch, cl, cl->agg->class_weight, len);
         if (err) {
             cl->qstats.drops++;
             return qdisc_drop(skb, sch, to_free);
         }

    // ...

     }

Similarly to CVE-2023-31436, "lmax" is increased without any bounds
checks according to the packet length "len". Usually this would not
impose a problem because packet sizes are naturally limited.

This is however not the actual packet length, rather the
"qdisc_pkt_len(skb)" which might apply size transformations according to
"struct qdisc_size_table" as created by "qdisc_get_stab()" in
net/sched/sch_api.c if the TCA_STAB option was set when modifying the qdisc.

A user may choose virtually any size using such a table.

As a result the same issue as in CVE-2023-31436 can occur, allowing heap
out-of-bounds read / writes in the kmalloc-8192 cache.
-------

We can create the issue with the following commands:

tc qdisc add dev $DEV root handle 1: stab mtu 2048 tsize 512 mpu 0 \
overhead 999999999 linklayer ethernet qfq
tc class add dev $DEV parent 1: classid 1:1 htb rate 6mbit burst 15k
tc filter add dev $DEV parent 1: matchall classid 1:1
ping -I $DEV 1.1.1.2

This is caused by incorrectly assuming that qdisc_pkt_len() returns a
length within the QFQ_MIN_LMAX < len < QFQ_MAX_LMAX.

Fixes: 462dbc91 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: NLion <nnamrec@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NPedro Tammela <pctammela@mojatatu.com>
Reviewed-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

Conflicts:
	net/sched/sch_qfq.c
Signed-off-by: NZhengchao Shao <shaozhengchao@huawei.com>