On 2018/8/15 23:41, Greg KH wrote:
> On Wed, Aug 15, 2018 at 03:24:32PM +0200, Greg KH wrote:
>> On Wed, Aug 15, 2018 at 09:20:59PM +0800, Mao Wenan wrote:
>>> There are five patches to fix CVE-2018-5390 in latest mainline
>>> branch, but only two patches exist in stable 4.4 and 3.18:
>>> dc6ae4d tcp: detect malicious patterns in tcp_collapse_ofo_queue()
>>> 5fbec48 tcp: avoid collapses in tcp_prune_queue() if possible
>>> but I have tested with these patches, and found the cpu usage was very high.
>>> test results:
>>> with fix patch： 78.2% ksoftirqd
>>> no fix patch： 90% ksoftirqd
>>>
>>> After analysing the codes of stable 4.4, and debuging the
>>> system, the search of ofo_queue(tcp ofo using a simple queue) cost more
>>> cycles.
>>> So I think only two patches can't fix the CVE-2018-5390.
>>> So I try to backport "tcp: use an RB tree for ooo receive queue" using RB
>>> tree
>>> instead of simple queue, then backport Eric Dumazet 5 fixed patches in
>>> mainline,
>>> good news is that ksoftirqd is turn to about 20%, which is the same with
>>> mainline now.
>>
>> Thanks for doing this work, I had some questions on the individual
>> patches. Can you address them and resend?
>
> Also, always cc: the stable@vger list when sending stable patches so
> that others can review and comment on them.
ok,I will resend patches later after refining them.
>
> thanks,
>
> greg k-h
>
> .
>
