8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 000000a0
pgd = 86b5da40
[000000a0] *pgd=86c2f003, *pmd=fe4d7003
Internal error: Oops: 207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 3488 Comm: iou-sqp-3479 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: 60000113
sp : 86bfdee0  ip : 86c4a080  fp : 86bfdf2c
r10: 00000000  r9 : 86bfc000  r8 : 00000000
r7 : 86c05000  r6 : 86a24300  r5 : 86a24354  r4 : 86c05000
r3 : 000000a0  r2 : 86bfc000  r1 : 000000a0  r0 : 86bfdef4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 86b5da40  DAC: fffffffd
Process iou-sqp-3479 (pid: 3488, stack limit = 0x86bfc210)
Stack: (0x86bfdee0 to 0x86bfe000)
dee0: 00000000 000000a0 00000000 86c4a080 802a6878 86bfdef4 86bfdef4 56b92eae
df00: 00000001 86c05000 86a24354 86a24300 00000000 00000000 86bfc000 00000000
df20: 86bfdfac 86bfdf30 80566f50 80561e60 86a24304 81f744cc 82a06d00 00000000
df40: 80384db8 86a24300 86ad5280 86a24354 00000000 00000000 00000000 86c4a080
df60: 802a6878 86bfdf64 86bfdf64 2d756f69 2d707173 39373433 80258400 56b92eae
df80: 00000000 86a24300 80566b80 00000000 00000000 00000000 00000000 00000000
dfa0: 00000000 86bfdfb0 80200114 80566b8c 00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 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 r9:86bfc000 r8:00000000 r7:00000000 r6:86a24300 r5:86a24354
 r4:86c05000
[<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x86bfdfb0 to 0x86bfdff8)
dfa0:                                     00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80566b80
 r4:86a24300
Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) 
---[ end trace 4ca10d525b1c67ef ]---