From: Toke Høiland-Jørgensen toke@toke.dk
stable inclusion from stable-v4.19.258 commit 5dac9b60b48ce8a3cd498c5680e8b5f0f4034461 category: bugfix bugzilla: 187862, https://gitee.com/src-openeuler/kernel/issues/I5WF14 CVE: CVE-2022-3586
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[ Upstream commit 2f09707d0c972120bf794cfe0f0c67e2c2ddb252 ]
Cong Wang noticed that the previous fix for sch_sfb accessing the queued skb after enqueueing it to a child qdisc was incomplete: the SFB enqueue function was also calling qdisc_qstats_backlog_inc() after enqueue, which reads the pkt len from the skb cb field. Fix this by also storing the skb len, and using the stored value to increment the backlog after enqueueing.
Fixes: 9efd23297cca ("sch_sfb: Don't assume the skb is still around after enqueueing to child") Signed-off-by: Toke Høiland-Jørgensen toke@toke.dk Acked-by: Cong Wang cong.wang@bytedance.com Link: https://lore.kernel.org/r/20220905192137.965549-1-toke@toke.dk Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Guo Mengqi guomengqi3@huawei.com Reviewed-by: chenweilong chenweilong@huawei.com Reviewed-by: Xiu Jianfeng xiujianfeng@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- net/sched/sch_sfb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c index 5e237f978075..4824c873dc78 100644 --- a/net/sched/sch_sfb.c +++ b/net/sched/sch_sfb.c @@ -285,6 +285,7 @@ static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch, {
struct sfb_sched_data *q = qdisc_priv(sch); + unsigned int len = qdisc_pkt_len(skb); struct Qdisc *child = q->qdisc; struct tcf_proto *fl; struct sfb_skb_cb cb; @@ -407,7 +408,7 @@ static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch, memcpy(&cb, sfb_skb_cb(skb), sizeof(cb)); ret = qdisc_enqueue(skb, child, to_free); if (likely(ret == NET_XMIT_SUCCESS)) { - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; increment_qlen(&cb, q); } else if (net_xmit_drop_count(ret)) {