8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 000000a0
pgd = 86539c40
[000000a0] *pgd=86d6b003, *pmd=fe426003
Internal error: Oops: 207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 12757 Comm: iou-sqp-12749 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 : 86e47ee0  ip : 86586180  fp : 86e47f2c
r10: 00000000  r9 : 86e46000  r8 : 00000000
r7 : 86e1b000  r6 : 86dab700  r5 : 86dab754  r4 : 86e1b000
r3 : 000000a0  r2 : 86e46000  r1 : 000000a0  r0 : 86e47ef4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 86539c40  DAC: fffffffd
Process iou-sqp-12749 (pid: 12757, stack limit = 0x86e46210)
Stack: (0x86e47ee0 to 0x86e48000)
7ee0: 00000000 000000a0 00000000 86586180 802a6878 86e47ef4 86e47ef4 56b92eae
7f00: 00000001 86e1b000 86dab754 86dab700 00000000 00000000 86e46000 00000000
7f20: 86e47fac 86e47f30 80566f50 80561e60 86dab704 81f744cc 82a06d00 00000000
7f40: 80384db8 86dab700 85650000 86dab754 00000000 00000000 00000000 86586180
7f60: 802a6878 86e47f64 86e47f64 2d756f69 2d707173 34373231 80250039 56b92eae
7f80: 00000000 86dab700 80566b80 00000000 00000000 00000000 00000000 00000000
7fa0: 00000000 86e47fb0 80200114 80566b8c 00000000 00000000 00000000 00000000
7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fe0: 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 r9:86e46000 r8:00000000 r7:00000000 r6:86dab700 r5:86dab754
 r4:86e1b000
[<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x86e47fb0 to 0x86e47ff8)
7fa0:                                     00000000 00000000 00000000 00000000
7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80566b80
 r4:86dab700
Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) 
---[ end trace 698ff3ed9da434c9 ]---