8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 000000a0 pgd = 86d93140 [000000a0] *pgd=85b79003, *pmd=fe555003 Internal error: Oops: 207 [#1] PREEMPT SMP ARM Modules linked in: CPU: 1 PID: 4152 Comm: iou-sqp-4145 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 : 86cabee0 ip : 83676180 fp : 86cabf2c r10: 00000000 r9 : 86caa000 r8 : 00000000 r7 : 86cc1800 r6 : 86d81200 r5 : 86d81254 r4 : 86cc1800 r3 : 000000a0 r2 : 86caa000 r1 : 000000a0 r0 : 86cabef4 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 30c5387d Table: 86d93140 DAC: 00000000 Process iou-sqp-4145 (pid: 4152, stack limit = 0x86caa210) Stack: (0x86cabee0 to 0x86cac000) bee0: 00000000 000000a0 00000000 83676180 802a6878 86cabef4 86cabef4 56b92eae bf00: 00000001 86cc1800 86d81254 86d81200 00000000 00000000 86caa000 00000000 bf20: 86cabfac 86cabf30 80566f50 80561e60 86d81204 81f744cc 82a06d00 00000000 bf40: 80384db8 86d81200 835ddd80 86d81254 00000000 00000000 00000000 83676180 bf60: 802a6878 86cabf64 86cabf64 2d756f69 2d707173 35343134 80258400 56b92eae bf80: 00000000 86d81200 80566b80 00000000 00000000 00000000 00000000 00000000 bfa0: 00000000 86cabfb0 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 r9:86caa000 r8:00000000 r7:00000000 r6:86d81200 r5:86d81254 r4:86cc1800 [<80566b80>] (io_sq_thread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158) Exception stack(0x86cabfb0 to 0x86cabff8) 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 r4:86d81200 Code: e28830a0 e50b3048 f593f000 e1a01003 (e1913f9f) ---[ end trace bd8f807d44fdd522 ]---