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由 Eric Dumazet 提交于
stable inclusion from stable-v4.19.207 commit 7c113506163a1ec6157927428eddd80038d2916e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5JPWX CVE: NA -------------------------------- [ Upstream commit c7c5e6ff ] syzbot found that forcing a big quantum attribute would crash hosts fast, essentially using this: tc qd replace dev eth0 root fq_codel quantum 4294967295 This is because fq_codel_dequeue() would have to loop ~2^31 times in : if (flow->deficit <= 0) { flow->deficit += q->quantum; list_move_tail(&flow->flowchain, &q->old_flows); goto begin; } SFQ max quantum is 2^19 (half a megabyte) Lets adopt a max quantum of one megabyte for FQ_CODEL. Fixes: 4b549a2e ("fq_codel: Fair Queue Codel AQM") Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: Nsyzbot <syzkaller@googlegroups.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NSasha Levin <sashal@kernel.org> Signed-off-by: NLu Wei <luwei32@huawei.com> Reviewed-by: NYue Haibing <yuehaibing@huawei.com> Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com> Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>
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