Re: [regression 6.1.y] discard/TRIM through RAID10 blocking (was: Re: Bug#1104460: linux-image-6.1.0-34-powerpc64le: Discard broken) with RAID10: BUG: kernel tried to execute user page (0) - exploit attempt?

[Salvatore Bonaccorso <carnil@debian.org>]

Hi Moritz,

On Mon, May 05, 2025 at 01:47:15PM +0200, Moritz Mühlenhoff wrote:
> Am Wed, Apr 30, 2025 at 05:55:20PM +0200 schrieb Salvatore Bonaccorso:
> > Hi
> > 
> > We got a regression report in Debian after the update from 6.1.133 to
> > 6.1.135. Melvin is reporting that discard/trimm trhough a RAID10 array
> > stalls idefintively. The full report is inlined below and originates
> > from https://bugs.debian.org/1104460 .
> 
> JFTR, we ran into the same problem with a few Wikimedia servers running
> 6.1.135 and RAID 10: The servers started to lock up once fstrim.service
> got started. Full oops messages are available at
> https://phabricator.wikimedia.org/P75746

Thanks for this aditional datapoints. Assuming you wont be able to
thest the other stable series where the commit d05af90d6218
("md/raid10: fix missing discard IO accounting") went in, might you at
least be able to test the 6.1.y branch with the commit reverted again
and manually trigger the issue?

If needed I can provide a test Debian package of 6.1.135 (or 6.1.137)
with the patch reverted. 

Regards,
Salvatore