Comment # 18 on bug 1160604 from Guillaume GARDET

The problem is back on obs-arm-2 host in OBS, with kernel 5.14.6 in Tumbleweed:
[ 2380s] [ 2287.115388][T20685] Unable to handle kernel paging request at
virtual address fffffffffffffdd0
[ 2380s] [ 2287.122121][T20685] Mem abort info:
[ 2380s] [ 2287.125116][T20685]   ESR = 0x96000004
[ 2380s] [ 2287.128094][T20685]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 2380s] [ 2287.153836][T20685]   SET = 0, FnV = 0
[ 2380s] [ 2287.156704][T20685]   EA = 0, S1PTW = 0
[ 2380s] [ 2287.160310][T20685]   FSC = 0x04: level 0 translation fault
[ 2380s] [ 2287.164863][T20685] Data abort info:
[ 2380s] [ 2287.167726][T20685]   ISV = 0, ISS = 0x00000004
[ 2380s] [ 2287.192746][T20685]   CM = 0, WnR = 0
[ 2380s] [ 2287.197319][T20685] swapper pgtable: 4k pages, 48-bit VAs,
pgdp=0000000041a9d000
[ 2380s] [ 2287.206677][T20685] [fffffffffffffdd0] pgd=0000000000000000,
p4d=0000000000000000
[ 2380s] [ 2287.216024][T20685] Internal error: Oops: 96000004 [#1] SMP
[ 2380s] [ 2287.242512][T20685] Modules linked in: sha2_ce sha256_arm64
qemu_fw_cfg overlay e1000 nls_iso8859_1 nls_cp437 vfat fat virtio_rng
virtio_blk virtio_mmio xfs btrfs blake2b_generic xor xor_neon raid6_pq
libcrc32c reiserfs ext4 mbcache jbd2 squashfs fuse dm_snapshot dm_bufio
dm_crypt essiv authenc trusted asn1_encoder tee dm_mod binfmt_misc loop sg
[ 2380s] [ 2287.293948][T20685] CPU: 0 PID: 20685 Comm: kworker/u8:9 Not
tainted 5.14.6-1-default #1 openSUSE Tumbleweed
c1872505db63fbf00d9a52001e44bfff60e82ba4
[ 2380s] [ 2287.310914][T20685] Hardware name: linux,dummy-virt (DT)
[ 2380s] [ 2287.317742][T20685] Workqueue: btrfs-delalloc btrfs_work_helper
[btrfs]
[ 2380s] [ 2287.326723][T20685] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO
BTYPE=--)
[ 2380s] [ 2287.335554][T20685] pc : submit_compressed_extents+0x4c/0x40c
[btrfs]
[ 2380s] [ 2287.344185][T20685] lr : async_cow_submit+0x50/0xd0 [btrfs]
[ 2380s] [ 2287.351864][T20685] sp : ffff8000184d3c50
[ 2380s] [ 2287.357041][T20685] x29: ffff8000184d3c60 x28: 0000000000000000
x27: ffffbda48d635000
[ 2380s] [ 2287.367200][T20685] x26: fffffffffffffdd0 x25: dead000000000100
x24: ffff000271672808
[ 2380s] [ 2287.377535][T20685] x23: ffff0000c7808410 x22: ffff000271672b48
x21: 0000000000000000
[ 2380s] [ 2287.387308][T20685] x20: ffff0000ca476000 x19: 0000000000000001
x18: 0000000000000000
[ 2380s] [ 2287.397152][T20685] x17: 0000000000000020 x16: ffffbda48bf5c1c0
x15: 08010a0304fe1201
[ 2380s] [ 2287.407122][T20685] x14: 0201040112011001 x13: ffff00027ebe8480
x12: 0000000000000020
[ 2380s] [ 2287.417248][T20685] x11: ffffbda48d650ca0 x10: ffff425df1505000 x9
: ffffbda45b008b50
[ 2380s] [ 2287.427189][T20685] x8 : fffffc00030b8048 x7 : fffffc00030b8040 x6
: 0000000000000000
[ 2380s] [ 2287.437034][T20685] x5 : dead000000000122 x4 : 0000000000000000 x3
: ffff0000c7808420
[ 2380s] [ 2287.447076][T20685] x2 : 0000000000000000 x1 : ffff000271672830 x0
: ffff000271672830
[ 2380s] [ 2287.457424][T20685] Call trace:
[ 2380s] [ 2287.461571][T20685]  submit_compressed_extents+0x4c/0x40c [btrfs
6c5d395590a945b218fd40a8a3d4ca1900960144]
[ 2380s] [ 2287.474127][T20685]  async_cow_submit+0x50/0xd0 [btrfs
6c5d395590a945b218fd40a8a3d4ca1900960144]
[ 2380s] [ 2287.485617][T20685]  btrfs_work_helper+0x134/0x4bc [btrfs
6c5d395590a945b218fd40a8a3d4ca1900960144]
[ 2380s] [ 2287.497624][T20685]  process_one_work+0x1e4/0x4a0
[ 2380s] [ 2287.503716][T20685]  worker_thread+0x174/0x56c
[ 2380s] [ 2287.509504][T20685]  kthread+0x12c/0x140
[ 2380s] [ 2287.514475][T20685]  ret_from_fork+0x10/0x18
[ 2380s] [ 2287.519980][T20685] Code: f9005fe2 d2800002 d108c2ba f9401700
(f9400357) 
[ 2380s] [ 2287.528698][T20685] ---[ end trace f6440f612969c083 ]---