Unable to handle kernel paging request at virtual address dfff80000000000c
Mem abort info:
  ESR = 0x96000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[dfff80000000000c] address between user and kernel address ranges
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 18451 Comm: syz-executor.1 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: linux,dummy-virt (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
pc : cdev_del+0x2c/0xb0 fs/char_dev.c:596
lr : tty_unregister_device drivers/tty/tty_io.c:3217 [inline]
lr : tty_unregister_device+0x108/0x194 drivers/tty/tty_io.c:3212
sp : ffff0000346af950
x29: ffff0000346af950 x28: 0000000000000000 
x27: 0000000000000001 x26: ffff0000305f9608 
x25: 1fffe00001dde266 x24: ffff00000e327208 
x23: ffff000013d67000 x22: 1fffe00001c64e41 
x21: 0000000000000001 x20: 0000000000000008 
x19: 0000000000000000 x18: ffff00006a391b48 
x17: 0000000000000000 x16: 0000000000000000 
x15: ffff80001a709810 x14: 1fffe000068d5eb6 
x13: 0000000000000000 x12: ffff6000068d5edf 
x11: 1fffe000068d5ede x10: ffff6000068d5ede 
x9 : 1fffe00001f9045d x8 : ffff00000fc822e8 
x7 : dfff800000000000 x6 : 00000000f3f3f3f3 
x5 : ffff80001a71d7a0 x4 : 1fffe00001f90339 
x3 : 000000000000000c x2 : 0000000000000003 
x1 : dfff800000000000 x0 : 0000000000000060 
Call trace:
 cdev_del+0x2c/0xb0 fs/char_dev.c:596
 tty_unregister_device drivers/tty/tty_io.c:3217 [inline]
 tty_unregister_device+0x108/0x194 drivers/tty/tty_io.c:3212
 gsmld_detach_gsm drivers/tty/n_gsm.c:2409 [inline]
 gsmld_close+0xac/0x21c drivers/tty/n_gsm.c:2478
 tty_ldisc_close+0xd0/0x140 drivers/tty/tty_ldisc.c:488
 tty_ldisc_kill+0x74/0x100 drivers/tty/tty_ldisc.c:636
 tty_ldisc_release+0x110/0x1c0 drivers/tty/tty_ldisc.c:809
 tty_release_struct+0x28/0xd0 drivers/tty/tty_io.c:1629
 tty_release+0x838/0xe74 drivers/tty/tty_io.c:1800
 __fput+0x1a0/0x6ac fs/file_table.c:280
 ____fput+0x14/0x20 fs/file_table.c:313
 task_work_run+0xd8/0x210 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 do_notify_resume+0x12e4/0x25fc arch/arm64/kernel/signal.c:939
 work_pending+0xc/0x35c
Code: 91018000 f2fbffe1 52800062 d343fc03 (38e16861) 
---[ end trace 9e0411171880a7e9 ]---