8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write
[00000018] *pgd=89aeb003, *pmd=fe21b003
Internal error: Oops: a07 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 18383 Comm: syz-executor.0 Not tainted 6.8.0-syzkaller #0
Hardware name: ARM-Versatile Express
PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2399 [inline]
PC is at do_pagemap_scan+0x294/0x6b4 fs/proc/task_mmu.c:2445
LR is at kmalloc_array include/linux/slab.h:665 [inline]
LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2394 [inline]
LR is at do_pagemap_scan+0x260/0x6b4 fs/proc/task_mmu.c:2445
pc : [<8059aed4>]    lr : [<8059aea0>]    psr: 20000013
sp : ec969e18  ip : 00000000  fp : ec969f04
r10: ec969e50  r9 : 83738c00  r8 : 00000000
r7 : 00000000  r6 : 00000000  r5 : 20ffb000  r4 : 8414e100
r3 : 20ffc000  r2 : 00000000  r1 : 00000000  r0 : 00000010
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 898fc440  DAC: fffffffd
Register r0 information: zero-size pointer
Register r1 information: NULL pointer
Register r2 information: NULL pointer
Register r3 information: non-paged memory
Register r4 information: slab mm_struct start 8414e100 pointer offset 0 size 712
Register r5 information: non-paged memory
Register r6 information: NULL pointer
Register r7 information: NULL pointer
Register r8 information: NULL pointer
Register r9 information: slab task_struct start 83738c00 pointer offset 0 size 3072
Register r10 information: 2-page vmalloc region starting at 0xec968000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796
Register r11 information: 2-page vmalloc region starting at 0xec968000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796
Register r12 information: NULL pointer
Process syz-executor.0 (pid: 18383, stack limit = 0xec968000)
Stack: (0xec969e18 to 0xec96a000)
9e00:                                                       00000000 00000000
9e20: 10000000 20000d80 00000001 00000000 00000000 20ffb000 00000000 00000000
9e40: 00000000 00000000 00000000 00000000 00000060 00000000 00000000 00000000
9e60: 20ffb000 00000000 20ffc000 00000000 00000000 00000000 20000d00 00000000
9e80: 00000000 10000000 ffffffff 00000000 00000000 00000000 00000000 00000000
9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000000
9ec0: 00000000 00000000 20000d00 00000000 c0606610 7eb68c21 ec969ef4 c0606610
9ee0: 00000000 82f29cc1 20000d80 00000003 83738c00 82f29cc0 ec969f14 ec969f08
9f00: 8059b31c 8059ac4c ec969fa4 ec969f18 8050d3f8 8059b300 83738c00 00000001
9f20: ecac8b10 83738c00 ec969f44 ec969f38 81882504 818823d0 ec969f5c ec969f48
9f40: 8024c680 8027ad68 40000000 ec969fb0 ec969f84 ec969f60 80203138 8024c63c
9f60: 8261ca0c ec969fb0 0006b3f0 ecac8b10 80203020 7eb68c21 ec969fac 00000000
9f80: 00000000 0014c2c8 00000036 80200288 83738c00 00000036 00000000 ec969fa8
9fa0: 80200060 8050d2ec 00000000 00000000 00000003 c0606610 20000d80 00000000
9fc0: 00000000 00000000 0014c2c8 00000036 7e8ee32e 7e8ee32f 003d0f00 76b030fc
9fe0: 76b02f08 76b02ef8 000167f8 00050bc0 60000010 00000003 00000000 00000000
Backtrace: 
[<8059ac40>] (do_pagemap_scan) from [<8059b31c>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2512)
 r10:82f29cc0 r9:83738c00 r8:00000003 r7:20000d80 r6:82f29cc1 r5:00000000
 r4:c0606610
[<8059b2f4>] (do_pagemap_cmd) from [<8050d3f8>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<8059b2f4>] (do_pagemap_cmd) from [<8050d3f8>] (do_vfs_ioctl fs/ioctl.c:858 [inline])
[<8059b2f4>] (do_pagemap_cmd) from [<8050d3f8>] (__do_sys_ioctl fs/ioctl.c:902 [inline])
[<8059b2f4>] (do_pagemap_cmd) from [<8050d3f8>] (sys_ioctl+0x118/0xc24 fs/ioctl.c:890)
[<8050d2e0>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66)
Exception stack(0xec969fa8 to 0xec969ff0)
9fa0:                   00000000 00000000 00000003 c0606610 20000d80 00000000
9fc0: 00000000 00000000 0014c2c8 00000036 7e8ee32e 7e8ee32f 003d0f00 76b030fc
9fe0: 76b02f08 76b02ef8 000167f8 00050bc0
 r10:00000036 r9:83738c00 r8:80200288 r7:00000036 r6:0014c2c8 r5:00000000
 r4:00000000
Code: e51b309c e51b208c e50b203c e3a02000 (e1c060f8) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	e51b309c 	ldr	r3, [fp, #-156]	@ 0xffffff64
   4:	e51b208c 	ldr	r2, [fp, #-140]	@ 0xffffff74
   8:	e50b203c 	str	r2, [fp, #-60]	@ 0xffffffc4
   c:	e3a02000 	mov	r2, #0
* 10:	e1c060f8 	strd	r6, [r0, #8] <-- trapping instruction