8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 000000a0
pgd = 86cb7400
[000000a0] *pgd=867ed003, *pmd=e1c31003
Internal error: Oops: 207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 4922 Comm: iou-sqp-4920 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: 600f0013
sp : 86cebee0  ip : 86868000  fp : 86cebf2c
r10: 00000000  r9 : 86cea000  r8 : 00000000
r7 : 86c4c000  r6 : 86b88200  r5 : 86b88254  r4 : 86c4c000
r3 : 000000a0  r2 : 86cea000  r1 : 000000a0  r0 : 86cebef4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 86cb7400  DAC: fffffffd
Process iou-sqp-4920 (pid: 4922, stack limit = 0x86cea210)
Stack: (0x86cebee0 to 0x86cec000)
bee0: 00000000 000000a0 00000000 86868000 802a6878 86cebef4 86cebef4 56b92eae
bf00: 00000001 86c4c000 86b88254 86b88200 00000000 00000000 86cea000 00000000
bf20: 86cebfac 86cebf30 80566f50 80561e60 86b88204 81f744cc 82a06d00 00000000
bf40: 80384db8 86b88200 869c5d80 86b88254 00000000 00000000 00000000 86868000
bf60: 802a6878 86cebf64 86cebf64 2d756f69 2d707173 30323934 80258400 56b92eae
bf80: 00000000 86b88200 80566b80 00000000 00000000 00000000 00000000 00000000
bfa0: 00000000 86cebfb0 80200114 80566b8c 00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 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 r9:86cea000 r8:00000000 r7:00000000 r6:86b88200 r5:86b88254
 r4:86c4c000
[<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x86cebfb0 to 0x86cebff8)
bfa0:                                     00000000 00000000 00000000 00000000
bfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80566b80
 r4:86b88200
Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) 
---[ end trace 1043aa0a11a9395d ]---