[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
2022-06-08T05:17:00Z

--- Comment #5 from Zorro Lang (zlang@redhat.com) ---
On Tue, Jun 07, 2022 at 05:05:01PM +0200, Alexander Gordeev wrote:
> On Mon, Jun 06, 2022 at 03:13:12PM -0700, Andrew Morton wrote:
> > (switched to email. Please respond via emailed reply-to-all, not via the
> > bugzilla web interface).
>
> Hi Zorro,
>
> Unfortunately, I am not able to reproduce the issue. Could you please
> clarify your test environment details and share your xfstests config?

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,
Zorro

[1]
CPU
Vendor IBM/S390
Model Name 8561
Family 0
Model 3126312
Stepping 0
Speed 0.0
Processors 2
Cores 0
Sockets 0
Hyper True
Flags edat dfp vxp vx vxe ldisp sie vxe2 highgprs etf3eh te vxd gs sort zarch
msa stfle dflt eimm esan3
Arch(s) s390x

Memory 4096 MB
NUMA Nodes 1

Disks
Model Size Logical sector size Physical sector size
3390/0c 41.03 GB / 38.21 GiB 4096 bytes 4096 bytes

[2]
# cat local.config
FSTYP=xfs
TEST_DEV=/dev/loop0
TEST_DIR=/mnt/fstests/TEST_DIR
SCRATCH_DEV=/dev/loop1
SCRATCH_MNT=/mnt/fstests/SCRATCH_DIR
LOGWRITES_DEV=/dev/loop2
MKFS_OPTIONS="-n size=65536 -m
crc=1,finobt=1,reflink=1,rmapbt=0,bigtime=1,inobtcount=1"
TEST_FS_MOUNT_OPTS=""

>
> Thanks!