Re: [syzbot] [mm?] kernel BUG in collapse_scan_file

From: David Hildenbrand (Arm)

Date: Thu Mar 19 2026 - 07:15:48 EST


>> "This isn't the kind of thing where you can just jump in with a one line
>> patch and actually be helpful, sorry."
>
>
> Yup, so again really I don't think the kernel should take the xarray debug patch
> until it is discussed and verified as correct on-list.
>
> See the discussion with Vlastimil.

Agreed.

>
>>
>> So I am clueless if there is a real problem there or whether it's just a
>> false positive. And whether (if it's a real problem) the simple fix
>> would actually be a good temporary fix ("make other bugs more likely").
>>
>> I can try finding some time to look into that, but pagecache code is not
>> particularly the code I'm familiar with ...
>
> I don't think we should waste our time on it, willy's series should be yoinked
> until it can prove itself for-sure well behaved.

I hear you. At the same time it has the smell of "test case fails, so
let's remove the test case" vibes.

Well, arguable, it's worse than a test case that fails :(

I'm fine with dropping that asap. At the same time, I hope we won't lose
our reminder that something possibly bad is broken upstream.

--
Cheers,

David