Re: [EXT] Re: [PATCH 0/5] net: atlantic: more fuzzing fixes

[Igor Russkikh]

Hi Grant,

Sorry for the delay, I was on vacation.
Thanks for working on this.

I'm adding here Dmitrii, to help me review the patches.
Dmitrii, here is a full series:

https://patchwork.kernel.org/project/netdevbpf/cover/20220418231746.2464800-1-grundler@xxxxxxxxxxxx/

Grant, I've reviewed and also quite OK with patches 1-4.

For patch 5 - why do you think we need these extra comparisons with software head/tail?
>From what I see in logic, only the size limiting check is enough there..

Other extra checks are tricky and non intuitive..

Regards,
  Igor

On 4/21/2022 9:53 PM, Grant Grundler wrote:
> External Email
> 
> ----------------------------------------------------------------------
> Igor,
> Will you have a chance to comment on this in the near future?
> Should someone else review/integrate these patches?
> 
> I'm asking since I've seen no comments in the past three days.
> 
> cheers,
> grant
> 
> 
> On Mon, Apr 18, 2022 at 4:17 PM Grant Grundler <grundler@xxxxxxxxxxxx> 
> wrote:
>>
>> The Chrome OS fuzzing team posted a "Fuzzing" report for atlantic driver
>> in Q4 2021 using Chrome OS v5.4 kernel and "Cable Matters
>> Thunderbolt 3 to 10 Gb Ethernet" (b0 version):
>>
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__docs.google.com_document_d_e_2PACX-2D1vT4oCGNhhy-5FAuUqpu6NGnW0N9HF-5Fjxf2kS7raOpOlNRqJNiTHAtjiHRthXYSeXIRTgfeVvsEt0qK9qK_pub&d=DwIBaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=3kUjVPjrPMvlbd3rzgP63W0eewvCq4D-kzQRqaXHOqU&m=QoxR8WoQQ-hpWu_tThQydP3-6zkRWACvRmj_7aY1qo2FG6DdPdI86vAYrfKQFMHX&s=620jqeSvQrGg6aotI35cWwQpjaL94s7TFeFh2cYSyvA&e=
>>
>> It essentially describes four problems:
>> 1) validate rxd_wb->next_desc_ptr before populating buff->next
>> 2) "frag[0] not initialized" case in aq_ring_rx_clean()
>> 3) limit iterations handling fragments in aq_ring_rx_clean()
>> 4) validate hw_head_ in hw_atl_b0_hw_ring_tx_head_update()
>>
>> I've added one "clean up" contribution:
>>     "net: atlantic: reduce scope of is_rsc_complete"
>>
>> I tested the "original" patches using chromeos-v5.4 kernel branch:
>>
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__chromium-2Dreview.googlesource.com_q_hashtag-3Apcinet-2Datlantic-2D2022q1-2B-28status-3Aopen-2520OR-2520status-3Amerged-29&d=DwIBaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=3kUjVPjrPMvlbd3rzgP63W0eewvCq4D-kzQRqaXHOqU&m=QoxR8WoQQ-hpWu_tThQydP3-6zkRWACvRmj_7aY1qo2FG6DdPdI86vAYrfKQFMHX&s=1a1YwJqrY-be2oDgGAG5oOyZDnqIok_2p5G-N8djo2I&e=
>>
>> The fuzzing team will retest using the chromeos-v5.4 patches and the b0 
>> HW.
>>
>> I've forward ported those patches to 5.18-rc2 and compiled them but am
>> currently unable to test them on 5.18-rc2 kernel (logistics problems).
>>
>> I'm confident in all but the last patch:
>>    "net: atlantic: verify hw_head_ is reasonable"
>>
>> Please verify I'm not confusing how ring->sw_head and ring->sw_tail
>> are used in hw_atl_b0_hw_ring_tx_head_update().
>>
>> Credit largely goes to Chrome OS Fuzzing team members:
>>     Aashay Shringarpure, Yi Chou, Shervin Oloumi
>>
>> cheers,
>> grant