8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 000000a0
pgd = 86c5a600
[000000a0] *pgd=86e1e003, *pmd=fe65e003
Internal error: Oops: 207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 6490 Comm: iou-sqp-6481 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: 600f0113
sp : 86af9ee0  ip : 83664100  fp : 86af9f2c
r10: 00000000  r9 : 86af8000  r8 : 00000000
r7 : 864f9800  r6 : 86d99000  r5 : 86d99054  r4 : 864f9800
r3 : 000000a0  r2 : 86af8000  r1 : 000000a0  r0 : 86af9ef4
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 86c5a600  DAC: 00000000
Process iou-sqp-6481 (pid: 6490, stack limit = 0x86af8210)
Stack: (0x86af9ee0 to 0x86afa000)
9ee0: 00000000 000000a0 00000000 83664100 802a6878 86af9ef4 86af9ef4 56b92eae
9f00: 00000001 864f9800 86d99054 86d99000 00000000 00000000 86af8000 00000000
9f20: 86af9fac 86af9f30 80566f50 80561e60 86d99004 81f744cc 82a06d00 00000000
9f40: 80384db8 86d99000 8366ee00 86d99054 00000000 00000000 00000000 83664100
9f60: 802a6878 86af9f64 86af9f64 2d756f69 2d707173 31383436 80258400 56b92eae
9f80: 00000000 86d99000 80566b80 00000000 00000000 00000000 00000000 00000000
9fa0: 00000000 86af9fb0 80200114 80566b8c 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 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 r9:86af8000 r8:00000000 r7:00000000 r6:86d99000 r5:86d99054
 r4:864f9800
[<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158)
Exception stack(0x86af9fb0 to 0x86af9ff8)
9fa0:                                     00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80566b80
 r4:86d99000
Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) 
---[ end trace 566f477d70b8437e ]---