8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address 00000018 when write
[00000018] *pgd=84dee003, *pmd=fc6bd003
Internal error: Oops: a05 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 UID: 0 PID: 3960 Comm: syz-executor.0 Not tainted 6.11.0-rc5-syzkaller #0
Hardware name: ARM-Versatile Express
PC is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2711 [inline]
PC is at do_pagemap_scan+0x2ac/0x6f8 fs/proc/task_mmu.c:2757
LR is at kmalloc_noprof include/linux/slab.h:685 [inline]
LR is at kmalloc_array_noprof include/linux/slab.h:726 [inline]
LR is at pagemap_scan_init_bounce_buffer fs/proc/task_mmu.c:2706 [inline]
LR is at do_pagemap_scan+0x278/0x6f8 fs/proc/task_mmu.c:2757
pc : [<805afe48>]    lr : [<805afe14>]    psr: 20000013
sp : dfc71e18  ip : dfc71e18  fp : dfc71f04
r10: 00000000  r9 : 00000000  r8 : 00000000
r7 : dfc71e50  r6 : 83e7d400  r5 : 20ffb000  r4 : 841ec900
r3 : 20ffc000  r2 : 00000000  r1 : 00000000  r0 : 00000010
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 84dec1c0  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 841ec900 pointer offset 0 size 712
Register r5 information: non-paged memory
Register r6 information: slab task_struct start 83e7d400 pointer offset 0 size 3072
Register r7 information: 2-page vmalloc region starting at 0xdfc70000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2781
Register r8 information: NULL pointer
Register r9 information: NULL pointer
Register r10 information: NULL pointer
Register r11 information: 2-page vmalloc region starting at 0xdfc70000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2781
Register r12 information: 2-page vmalloc region starting at 0xdfc70000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2781
Process syz-executor.0 (pid: 3960, stack limit = 0xdfc70000)
Stack: (0xdfc71e18 to 0xdfc72000)
1e00:                                                       00000000 00000000
1e20: 00000000 00000000 20000200 00000001 20ffb000 00000000 00000000 00000000
1e40: 00000000 00000000 00000000 00000000 00000060 00000000 00000000 00000000
1e60: 20ffb000 00000000 20ffc000 00000000 00000000 00000000 20000140 00000000
1e80: 00000000 10000000 ffffffff 00000000 00000000 00000000 00000000 00000000
1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000000
1ec0: 00000000 00000000 20000140 00000000 c0606610 2072c806 dfc71ef4 c0606610
1ee0: 00000000 8349fd81 20000200 8349fd80 00000003 83e7d400 dfc71f14 dfc71f08
1f00: 805b02bc 805afba8 dfc71fa4 dfc71f18 80520dac 805b02a0 83e7d400 00000001
1f20: ecac8b10 83e7d400 dfc71f44 dfc71f38 8197c3b8 8197c288 dfc71f5c dfc71f48
1f40: 8024bb58 8027b56c 40000000 dfc71fb0 dfc71f84 dfc71f60 80202dd8 8024bb14
1f60: 8261c9cc dfc71fb0 0006b3e0 ecac8b10 80202cc0 2072c806 dfc71fac 00000000
1f80: 00000000 0014c2c8 00000036 8020029c 83e7d400 00000036 00000000 dfc71fa8
1fa0: 80200060 80520c84 00000000 00000000 00000003 c0606610 20000200 00000000
1fc0: 00000000 00000000 0014c2c8 00000036 7eaef32e 7eaef32f 003d0f00 76b280fc
1fe0: 76b27f08 76b27ef8 000167e8 00050bb0 60000010 00000003 00000000 00000000
Call trace: 
[<805afb9c>] (do_pagemap_scan) from [<805b02bc>] (do_pagemap_cmd+0x28/0x34 fs/proc/task_mmu.c:2824)
 r10:83e7d400 r9:00000003 r8:8349fd80 r7:20000200 r6:8349fd81 r5:00000000
 r4:c0606610
[<805b0294>] (do_pagemap_cmd) from [<80520dac>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<805b0294>] (do_pagemap_cmd) from [<80520dac>] (do_vfs_ioctl fs/ioctl.c:861 [inline])
[<805b0294>] (do_pagemap_cmd) from [<80520dac>] (__do_sys_ioctl fs/ioctl.c:905 [inline])
[<805b0294>] (do_pagemap_cmd) from [<80520dac>] (sys_ioctl+0x134/0xda4 fs/ioctl.c:893)
[<80520c78>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xdfc71fa8 to 0xdfc71ff0)
1fa0:                   00000000 00000000 00000003 c0606610 20000200 00000000
1fc0: 00000000 00000000 0014c2c8 00000036 7eaef32e 7eaef32f 003d0f00 76b280fc
1fe0: 76b27f08 76b27ef8 000167e8 00050bb0
 r10:00000036 r9:83e7d400 r8:8020029c r7:00000036 r6:0014c2c8 r5:00000000
 r4:00000000
Code: e51b309c e51b108c e50b103c e3a01000 (e1c080f8) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	e51b309c 	ldr	r3, [fp, #-156]	@ 0xffffff64
   4:	e51b108c 	ldr	r1, [fp, #-140]	@ 0xffffff74
   8:	e50b103c 	str	r1, [fp, #-60]	@ 0xffffffc4
   c:	e3a01000 	mov	r1, #0
* 10:	e1c080f8 	strd	r8, [r0, #8] <-- trapping instruction