syzbot

8<--- cut here ---
Unable to handle kernel paging request at virtual address fee000f0 when write
[fee000f0] *pgd=80000080007003, *pmd=00000000
Internal error: Oops: a06 [#1] SMP ARM
Modules linked in:
CPU: 0 UID: 0 PID: 4088 Comm: syz.2.16 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT 
Hardware name: ARM-Versatile Express
PC is at __raw_writeb arch/arm/include/asm/io.h:88 [inline]
PC is at parport_attach drivers/comedi/drivers/comedi_parport.c:289 [inline]
PC is at parport_attach+0x174/0x1d0 drivers/comedi/drivers/comedi_parport.c:224
LR is at parport_attach drivers/comedi/drivers/comedi_parport.c:289 [inline]
LR is at parport_attach+0x164/0x1d0 drivers/comedi/drivers/comedi_parport.c:224
pc : [<81398ba8>]    lr : [<81398b98>]    psr: 60000013
sp : e05e1d38  ip : e05e1d38  fp : e05e1d5c
r10: 82b15078  r9 : 00000003  r8 : 841493c0
r7 : e05e1d98  r6 : 841493c0  r5 : 00000000  r4 : 00000000
r3 : fee000f0  r2 : 81e14f0c  r1 : 00000001  r0 : 81398818
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 85588d40  DAC: fffffffd
Register r0 information: non-slab/vmalloc memory
Register r1 information: non-paged memory
Register r2 information: non-slab/vmalloc memory
Register r3 information: 0-page vmalloc region starting at 0xfee00000 allocated at pci_reserve_io+0x0/0x38 arch/arm/mm/mmu.c:1055
Register r4 information: NULL pointer
Register r5 information: NULL pointer
Register r6 information: slab kmalloc-192 start 841493c0 pointer offset 0 size 192
Register r7 information: 2-page vmalloc region starting at 0xe05e0000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2599
Register r8 information: slab kmalloc-192 start 841493c0 pointer offset 0 size 192
Register r9 information: non-paged memory
Register r10 information: non-slab/vmalloc memory
Register r11 information: 2-page vmalloc region starting at 0xe05e0000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2599
Register r12 information: 2-page vmalloc region starting at 0xe05e0000 allocated at kernel_clone+0xac/0x3e4 kernel/fork.c:2599
Process syz.2.16 (pid: 4088, stack limit = 0xe05e0000)
Stack: (0xe05e1d38 to 0xe05e2000)
1d20:                                                       823f88f8 841493c0
1d40: 829c4b18 829c4b18 81e153cc 00000000 e05e1d94 e05e1d60 81394c60 81398a40
1d60: b5403587 00000000 83308000 20000080 841493c0 b5403587 20000080 83308000
1d80: 40946400 00000003 e05e1e4c e05e1d98 813908f0 81394b68 656d6f63 705f6964
1da0: 6f707261 00007472 00000000 000000f0 80008000 00000001 0000000a 00000000
1dc0: 00000000 10000001 00000001 00001000 00000001 00000008 00000001 00000006
1de0: 00000004 0000ffff 00000006 ffffffa7 00000009 fffffffd 00000005 000003ff
1e00: 00010000 00000800 0000e2df 00000009 000000ff 00000000 00000003 00000007
1e20: 00000005 00000005 00000000 444c0355 00000000 84fb0240 841493c0 20000080
1e40: e05e1f14 e05e1e50 813918a4 81390824 00000000 00000000 00000000 444c0355
1e60: 00000000 00000000 8246a3fc 0000005f 83ff3458 841493f0 8419275c 83308000
1e80: e05e1ee4 e05e1e90 8079688c 8078cb7c 00000064 00000001 00000000 e05e1eac
1ea0: 84e83490 8357be58 00006400 0000000b e05e1ea0 00000000 00000000 444c0355
1ec0: 84fb0240 40946400 20000080 20000080 00000003 84fb0240 e05e1ef4 e05e1ee8
1ee0: 807969ac 444c0355 e05e1f14 40946400 00000000 84fb0240 20000080 00000003
1f00: 84fb0240 83308000 e05e1fa4 e05e1f18 8056f16c 813912d4 e05e1f4c e05e1f28
1f20: 80349a98 8034cdb4 81a2db68 81a2da38 e05e1f54 e05e1f40 8026203c 7ead2920
1f40: e05e1fa4 e05e1f50 8034a2e0 803499a4 00000000 7ead2920 ffffffff 80234128
1f60: 00000000 00000000 00000000 00000000 00000000 444c0355 e05e1fac 00000000
1f80: 00000000 002f6300 00000036 8020029c 83308000 00000036 00000000 e05e1fa8
1fa0: 80200060 8056f048 00000000 00000000 00000003 40946400 20000080 00000000
1fc0: 00000000 00000000 002f6300 00000036 00000000 002f62d4 0000047b 00000000
1fe0: 7ead2780 7ead2770 000193a4 00131f40 60000010 00000003 00000000 00000000
Call trace: 
[<81398a34>] (parport_attach) from [<81394c60>] (comedi_device_attach+0x104/0x240 drivers/comedi/drivers.c:996)
 r6:00000000 r5:81e153cc r4:829c4b18
[<81394b5c>] (comedi_device_attach) from [<813908f0>] (do_devconfig_ioctl+0xd8/0x1e0 drivers/comedi/comedi_fops.c:855)
 r10:00000003 r9:40946400 r8:83308000 r7:20000080 r6:b5403587 r5:841493c0
 r4:20000080
[<81390818>] (do_devconfig_ioctl) from [<813918a4>] (comedi_unlocked_ioctl+0x5dc/0x1b94 drivers/comedi/comedi_fops.c:2136)
 r6:20000080 r5:841493c0 r4:84fb0240
[<813912c8>] (comedi_unlocked_ioctl) from [<8056f16c>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<813912c8>] (comedi_unlocked_ioctl) from [<8056f16c>] (do_vfs_ioctl fs/ioctl.c:861 [inline])
[<813912c8>] (comedi_unlocked_ioctl) from [<8056f16c>] (__do_sys_ioctl fs/ioctl.c:905 [inline])
[<813912c8>] (comedi_unlocked_ioctl) from [<8056f16c>] (sys_ioctl+0x130/0xdc8 fs/ioctl.c:893)
 r10:83308000 r9:84fb0240 r8:00000003 r7:20000080 r6:84fb0240 r5:00000000
 r4:40946400
[<8056f03c>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:67)
Exception stack(0xe05e1fa8 to 0xe05e1ff0)
1fa0:                   00000000 00000000 00000003 40946400 20000080 00000000
1fc0: 00000000 00000000 002f6300 00000036 00000000 002f62d4 0000047b 00000000
1fe0: 7ead2780 7ead2770 000193a4 00131f40
 r10:00000036 r9:83308000 r8:8020029c r7:00000036 r6:002f6300 r5:00000000
 r4:00000000
Code: e596306c e3a04000 e7f33053 e2433612 (e5c34000) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	e596306c 	ldr	r3, [r6, #108]	@ 0x6c
   4:	e3a04000 	mov	r4, #0
   8:	e7f33053 	ubfx	r3, r3, #0, #20
   c:	e2433612 	sub	r3, r3, #18874368	@ 0x1200000
* 10:	e5c34000 	strb	r4, [r3] <-- trapping instruction