8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write
[00000018] *pgd=8712b003, *pmd=df73e003
Internal error: Oops: a07 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 6707 Comm: syz-executor.0 Not tainted 6.7.0-rc1-syzkaller #0
Hardware name: ARM-Versatile Express
PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2367 [inline]
PC is at do_pagemap_scan+0x308/0x698 fs/proc/task_mmu.c:2414
LR is at 0x10
pc : [<80581844>]    lr : [<00000010>]    psr: 20000013
sp : ee4fddd0  ip : 00000000  fp : ee4fdeb4
r10: ee4fde00  r9 : 00000000  r8 : 836b1800
r7 : 00000000  r6 : 82f9c300  r5 : 20ff9000  r4 : 00000000
r3 : 20ffa000  r2 : 00000000  r1 : 00000000  r0 : 00000000
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 834ebf80  DAC: 00000000
Register r0 information: NULL pointer
Register r1 information: NULL pointer
Register r2 information: NULL pointer
Register r3 information: non-paged memory
Register r4 information: NULL pointer
Register r5 information: non-paged memory
Register r6 information: slab mm_struct start 82f9c300 pointer offset 0 size 712
Register r7 information: NULL pointer
Register r8 information: slab task_struct start 836b1800 pointer offset 0 size 3072
Register r9 information: NULL pointer
Register r10 information: 2-page vmalloc region starting at 0xee4fc000 allocated at kernel_clone+0xac/0x41c kernel/fork.c:2907
Register r11 information: 2-page vmalloc region starting at 0xee4fc000 allocated at kernel_clone+0xac/0x41c kernel/fork.c:2907
Register r12 information: NULL pointer
Process syz-executor.0 (pid: 6707, stack limit = 0xee4fc000)
Stack: (0xee4fddd0 to 0xee4fe000)
ddc0:                                     00000000 00000000 06000000 20000100
dde0: 20ff9000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
de00: 00000060 00000000 00000000 00000000 20ff9000 00000000 20ffa000 00000000
de20: 00000000 00000000 20000080 00000000 00000000 06000000 ffffffff 00000000
de40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
de60: 00000000 00000000 00000010 00000000 00000000 00000000 20000080 00000000
de80: c0606610 11acd74c ee4fdea4 c0606610 00000000 87705b41 20000100 87705b40
dea0: 00000003 836b1800 ee4fdec4 ee4fdeb8 80581bfc 80581548 ee4fdfa4 ee4fdec8
dec0: 804f9b7c 80581be0 000509d0 00000000 00000000 00000000 ee4fdf04 ee4fdee8
dee0: 8020c0ac 8020d078 00000000 00000001 8185ccc0 ecac8b10 ee4fdf44 ee4fdf08
df00: 8020d100 8020c094 00000000 00000000 8020c954 ee4fdfac 836b1800 00000001
df20: ecac8b10 836b1800 ee4fdf44 ee4fdf38 81851684 81851554 ee4fdf5c ee4fdf48
df40: 8024c610 802799e0 40000000 ee4fdfb0 ee4fdf84 ee4fdf60 802030e4 8024c5cc
df60: 8261c928 ee4fdfb0 0006b200 ecac8b10 80202fcc 11acd74c ee4fdfac 00000000
df80: 00000000 0014c2c0 00000036 80200288 836b1800 00000036 00000000 ee4fdfa8
dfa0: 80200060 804f9a70 00000000 00000000 00000003 c0606610 20000100 00000000
dfc0: 00000000 00000000 0014c2c0 00000036 7ed8332e 7ed8332f 003d0f00 76b940fc
dfe0: 76b93f08 76b93ef8 00016680 000509d0 60000010 00000003 00000000 00000000
Backtrace: 
[<8058153c>] (do_pagemap_scan) from [<80581bfc>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2478)
 r10:836b1800 r9:00000003 r8:87705b40 r7:20000100 r6:87705b41 r5:00000000
 r4:c0606610
[<80581bd4>] (do_pagemap_cmd) from [<804f9b7c>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<80581bd4>] (do_pagemap_cmd) from [<804f9b7c>] (do_vfs_ioctl fs/ioctl.c:831 [inline])
[<80581bd4>] (do_pagemap_cmd) from [<804f9b7c>] (__do_sys_ioctl fs/ioctl.c:869 [inline])
[<80581bd4>] (do_pagemap_cmd) from [<804f9b7c>] (sys_ioctl+0x118/0xb58 fs/ioctl.c:857)
[<804f9a64>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66)
Exception stack(0xee4fdfa8 to 0xee4fdff0)
dfa0:                   00000000 00000000 00000003 c0606610 20000100 00000000
dfc0: 00000000 00000000 0014c2c0 00000036 7ed8332e 7ed8332f 003d0f00 76b940fc
dfe0: 76b93f08 76b93ef8 00016680 000509d0
 r10:00000036 r9:836b1800 r8:80200288 r7:00000036 r6:0014c2c0 r5:00000000
 r4:00000000
Code: e51b2098 e51b108c e50b103c e3a01000 (e1ce00f8) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	e51b2098 	ldr	r2, [fp, #-152]	@ 0xffffff68
   4:	e51b108c 	ldr	r1, [fp, #-140]	@ 0xffffff74
   8:	e50b103c 	str	r1, [fp, #-60]	@ 0xffffffc4
   c:	e3a01000 	mov	r1, #0
* 10:	e1ce00f8 	strd	r0, [lr, #8] <-- trapping instruction