8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write
[00000018] *pgd=8d89a003, *pmd=feb53003
Internal error: Oops: a07 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 25048 Comm: syz-executor.1 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:2400 [inline]
PC is at do_pagemap_scan+0x294/0x6b4 fs/proc/task_mmu.c:2446
LR is at kmalloc_array include/linux/slab.h:665 [inline]
LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2395 [inline]
LR is at do_pagemap_scan+0x260/0x6b4 fs/proc/task_mmu.c:2446
pc : [<8059adec>]    lr : [<8059adb8>]    psr: 20000013
sp : dff81e18  ip : 00000000  fp : dff81f04
r10: dff81e50  r9 : 83e8e000  r8 : 00000000
r7 : 00000000  r6 : 00000000  r5 : 20008000  r4 : 840ce700
r3 : 20ffa000  r2 : 00000000  r1 : 00000000  r0 : 00000010
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 8b89f800  DAC: 00000000
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 840ce700 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 83e8e000 pointer offset 0 size 3072
Register r10 information: 2-page vmalloc region starting at 0xdff80000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796
Register r11 information: 2-page vmalloc region starting at 0xdff80000 allocated at kernel_clone+0xac/0x3cc kernel/fork.c:2796
Register r12 information: NULL pointer
Process syz-executor.1 (pid: 25048, stack limit = 0xdff80000)
Stack: (0xdff81e18 to 0xdff82000)
1e00:                                                       00000000 00000000
1e20: 10000000 20000240 00000001 00000000 00000000 20008000 00000000 00000000
1e40: 00000000 00000000 00000000 00000000 00000060 00000000 00000000 00000000
1e60: 20008000 00000000 20ffa000 00000000 00000000 00000000 200000c0 00000000
1e80: 00000000 10000000 ffffffff 00000000 00000000 00000000 00000000 00000000
1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000000
1ec0: 00000000 00000000 200000c0 00000000 c0606610 0c517bf2 dff81ef4 c0606610
1ee0: 00000000 848850c1 20000240 00000003 83e8e000 848850c0 dff81f14 dff81f08
1f00: 8059b234 8059ab64 dff81fa4 dff81f18 8050decc 8059b218 83e8e000 00000001
1f20: ecac8b10 83e8e000 dff81f44 dff81f38 8187c084 8187bf50 dff81f5c dff81f48
1f40: 8024c6b8 8027af40 40000000 dff81fb0 dff81f84 dff81f60 80203138 8024c674
1f60: 8261ca38 dff81fb0 0006b3f0 ecac8b10 80203020 0c517bf2 dff81fac 00000000
1f80: 00000000 0014c2c8 00000036 80200288 83e8e000 00000036 00000000 dff81fa8
1fa0: 80200060 8050ddc0 00000000 00000000 00000003 c0606610 20000240 00000000
1fc0: 00000000 00000000 0014c2c8 00000036 7ef1f32e 7ef1f32f 003d0f00 76b290fc
1fe0: 76b28f08 76b28ef8 000167f8 00050bc0 60000010 00000003 00000000 00000000
Backtrace: 
[<8059ab58>] (do_pagemap_scan) from [<8059b234>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2513)
 r10:848850c0 r9:83e8e000 r8:00000003 r7:20000240 r6:848850c1 r5:00000000
 r4:c0606610
[<8059b20c>] (do_pagemap_cmd) from [<8050decc>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<8059b20c>] (do_pagemap_cmd) from [<8050decc>] (do_vfs_ioctl fs/ioctl.c:858 [inline])
[<8059b20c>] (do_pagemap_cmd) from [<8050decc>] (__do_sys_ioctl fs/ioctl.c:902 [inline])
[<8059b20c>] (do_pagemap_cmd) from [<8050decc>] (sys_ioctl+0x118/0xc24 fs/ioctl.c:890)
[<8050ddb4>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66)
Exception stack(0xdff81fa8 to 0xdff81ff0)
1fa0:                   00000000 00000000 00000003 c0606610 20000240 00000000
1fc0: 00000000 00000000 0014c2c8 00000036 7ef1f32e 7ef1f32f 003d0f00 76b290fc
1fe0: 76b28f08 76b28ef8 000167f8 00050bc0
 r10:00000036 r9:83e8e000 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