8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 000000a0
pgd = 86f0ee40
[000000a0] *pgd=86cff003, *pmd=fe6a6003
Internal error: Oops: 207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 6746 Comm: iou-sqp-6740 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
PC is at atomic_add arch/arm/include/asm/atomic.h:223 [inline]
PC is at atomic_inc include/linux/atomic-fallback.h:372 [inline]
PC is at io_uring_cancel_sqpoll+0xac/0x1a0 fs/io_uring.c:8926
LR is at io_sq_thread+0x3d0/0x6f8 fs/io_uring.c:6772
pc : [<80561f00>]    lr : [<80566f50>]    psr: 60000013
sp : 86fafee0  ip : 86ed4100  fp : 86faff2c
r10: 00000000  r9 : 86fae000  r8 : 00000000
r7 : 867ea000  r6 : 835a7100  r5 : 835a7154  r4 : 867ea000
r3 : 000000a0  r2 : 86fae000  r1 : 000000a0  r0 : 86fafef4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 86f0ee40  DAC: fffffffd
Process iou-sqp-6740 (pid: 6746, stack limit = 0x86fae210)
Stack: (0x86fafee0 to 0x86fb0000)
fee0: 00000000 000000a0 00000000 86ed4100 802a6878 86fafef4 86fafef4 56b92eae
ff00: 00000001 867ea000 835a7154 835a7100 00000000 00000000 86fae000 00000000
ff20: 86faffac 86faff30 80566f50 80561e60 835a7104 81f744cc 82a06d00 00000000
ff40: 80384db8 835a7100 83746880 835a7154 00000000 00000000 00000000 86ed4100
ff60: 802a6878 86faff64 86faff64 2d756f69 2d707173 30343736 80258400 56b92eae
ff80: 00000000 835a7100 80566b80 00000000 00000000 00000000 00000000 00000000
ffa0: 00000000 86faffb0 80200114 80566b8c 00000000 00000000 00000000 00000000
ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
Backtrace: 
[<80561e54>] (io_uring_cancel_sqpoll) from [<80566f50>] (io_sq_thread+0x3d0/0x6f8 fs/io_uring.c:6772)
 r10:00000000 r9:86fae000 r8:00000000 r7:00000000 r6:835a7100 r5:835a7154
 r4:867ea000
[<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x86faffb0 to 0x86fafff8)
ffa0:                                     00000000 00000000 00000000 00000000
ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ffe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80566b80
 r4:835a7100
Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) 
---[ end trace af755cd571f5e657 ]---