netdev - Re: [Intel-wired-lan] [PATCH iwl-next v3] ice: Reset VF on Tx MDD event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7ded72b3-4c22-43d4-a5b5-191ef643c6c1@linux.intel.com>
Date: Fri, 29 Mar 2024 12:39:24 +0100
From: Marcin Szycik <marcin.szycik@...ux.intel.com>
To: Simon Horman <horms@...nel.org>
Cc: Wojciech Drewek <wojciech.drewek@...el.com>, netdev@...r.kernel.org,
 pawel.chmielewski@...el.com, anthony.l.nguyen@...el.com,
 Liang-Min Wang <liang-min.wang@...el.com>, intel-wired-lan@...ts.osuosl.org
Subject: Re: [Intel-wired-lan] [PATCH iwl-next v3] ice: Reset VF on Tx MDD
 event



On 29.03.2024 12:31, Marcin Szycik wrote:
> 
> 
> On 28.03.2024 18:34, Simon Horman wrote:
>> On Tue, Mar 26, 2024 at 05:44:55PM +0100, Marcin Szycik wrote:
>>> In cases when VF sends malformed packets that are classified as malicious,
>>> sometimes it causes Tx queue to freeze. This frozen queue can be stuck
>>> for several minutes being unusable. This behavior can be reproduced with
>>> a faulty userspace app running on VF.
>>>
>>> When Malicious Driver Detection event occurs and the mdd-auto-reset-vf
>>> private flag is set, perform a graceful VF reset to quickly bring VF back
>>> to operational state. Add a log message to notify about the cause of
>>> the reset. Add a helper for this to be reused for both TX and RX events.
>>>
>>> Reviewed-by: Wojciech Drewek <wojciech.drewek@...el.com>
>>> Co-developed-by: Liang-Min Wang <liang-min.wang@...el.com>
>>> Signed-off-by: Liang-Min Wang <liang-min.wang@...el.com>
>>> Signed-off-by: Marcin Szycik <marcin.szycik@...ux.intel.com>
>>
>> Hi Marcin,
>>
>> If I read this correctly then a reset may be performed for several
>> different conditions - values of different registers - for a VF
>> as checked in a for loop.
>>
>> I am wondering if multiple resets could occur for the same VF within
>> an iteration of the for loop - because more than one of the conditions is
>> met. And, if so, is this ok?
> 
> Hi Simon,
> 
> Good point. Nothing too bad should happen, as ice_reset_vf() acquires mutex lock

Sorry, that mutex doesn't matter much here, as we'd call another ice_reset_vf()
after previous one is done anyway.

> (in fact two locks), so several resets would just happen in sequence. However,
> it doesn't make much sense to reset VF multiple times, so maybe instead of issuing
> reset on each condition, I'll set some flag, and after checking all registers I'll
> trigger reset if that flag is set. What do you think?
> 
> Thanks,
> Marcin