[Bug 216073] [s390x] kernel BUG at mm/usercopy.c:101! usercopy: Kernel memory exposure attempt detected from vmalloc 'n o area' (offset 0, size 1)!

bugzilla-daemon
2022-06-09T02:49:34Z

--- Comment #7 from Zorro Lang (zlang@redhat.com) ---
On Wed, Jun 08, 2022 at 09:13:12PM +0200, Alexander Gordeev wrote:
> On Wed, Jun 08, 2022 at 10:19:22AM +0800, Zorro Lang wrote:
> > One of the test environment details as [1]. The xfstests config as [2].
> > It's easier to reproduce on 64k directory size xfs by running xfstests
> > auto group.
>
>
> Thanks for the details, Zorro!
>
> Do you create test and scratch device with xfs_io, as README suggests?
> If yes, what are sizes of the files?

# fallocate -l 5G /home/test_dev.img
# fallocate -l 10G /home/scratch_dev.img
Then create loop devices.

> Also, do you run always xfs/auto or xfs/294 hits for you reliably?

100% for on my testing, I tried 10 times, then hit it 10 times last
weekend. Will test again this week.

>
> Thanks!