Re: [PATCH 7.0.y,6.18.y 0/2] Backport io_uring commit to affected

[Jens Axboe <axboe@kernel.dk>]

On 5/8/26 1:52 AM, Harshit Mogalapalli wrote:
> Hi Jens and Pavel,
> 
> On 08/05/26 07:37, Pavel Begunkov wrote:
>> On 5/7/26 23:46, Jens Axboe wrote:
>>> On 5/7/26 4:41 PM, Jens Axboe wrote:
>>>> On 5/7/26 6:42 AM, Harshit Mogalapalli wrote:
>>>>> Hi Jens and stable maintainers,
>>>>>
>>>>> The intent of this series is to backport commit: 770594e78c39
>>>>> ("io_uring/zcrx: warn on freelist violations") to 6.18.y and 7.0.y.
>>>>>
>>>>> This above commit likely is fixing commit: 34a3e60821ab ("io_uring/ zcrx:
>>>>> implement zerocopy receive pp memory provider") in 6.18.y and 7.0.y.
>>>>>
>>>>> Pulled in a prerequisite to cleanly apply the fix. Only build tested.
>>>>
>>>> I don't think these are actually required, but at the same time it does
>>>> not hurt to add them. I'll leave that to Pavel to decide.
>>>>
>>>> In any case, thanks for doing the backports!
>>>
>>> Adding Pavel, I had assumed he was already on the email, as he's the
>>> maintainer for that file.
>>
>> What's motivation for this? I don't mind to have it (after review),
>> but it's not a fix, and I know people want it in stable to claim a
>> hallucinated CVE, and the CVE part is not going to happen.
>>
> 
> Sure, thanks for sharing this. I was reading this:
> https://ze3tar.github.io/post-zcrx.html and thought of sending
> backports to affected-stated stable branches. I looked up at the fix
> and checked probable broken commit and sent these backports. If the
> report is bogus, I think we should leave these but if its safe to
> backport these I think we should ?

I already told that guy that his hallucinated garbage is just plain
wrong. Did you notice in that post how part of the procedure is writing
to /proc/sys/kernel/modprobe? Which you need to be CAP_SYS_ADMIN/root to
do? And if you are root already, then wtf is the point of it. It's also
flagging the wrong commit, the related one fixing an actual bug is:

003049b1c4fb ("io_uring/zcrx: fix user_ref race between scrub and refill paths")

which is why I said this series is fine to do a consistency backport, as
it may make further backports easier, but in no way is it actually
fixing anything.

tldr - blog post is mostly hallucinated garbage made to look like some
novel or new thing, when it very much is not. Author said he'd update
it.

-- 
Jens Axboe