RBP: 00007f89cb5adca0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007ffde53501bf R14: 00007f89cb5ae9c0 R15: 000000000119bf8c
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 19159 Comm: syz-executor.5 Not tainted 4.14.215-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888097254580 task.stack: ffff8880a1978000
RIP: 0010:cdev_del+0x22/0x90 fs/char_dev.c:602
RSP: 0018:ffff8880a197fca0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880af64ad00 RCX: 0000000000000000
RDX: 000000000000000c RSI: ffff888097254e08 RDI: 0000000000000064
RBP: 0000000000000000 R08: ffffffff8b9b1890 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880af64ad08
R13: ffff8880af7d50c8 R14: ffff8880ab77f300 R15: ffff88809c06a398
FS:  0000000002da3940(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30322000 CR3: 00000000afad0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tty_unregister_device drivers/tty/tty_io.c:3046 [inline]
 tty_unregister_device+0x101/0x1a0 drivers/tty/tty_io.c:3041
 gsmld_detach_gsm drivers/tty/n_gsm.c:2303 [inline]
 gsmld_close+0xaa/0x1f0 drivers/tty/n_gsm.c:2372
 tty_ldisc_close+0x8c/0xc0 drivers/tty/tty_ldisc.c:505
 tty_ldisc_kill drivers/tty/tty_ldisc.c:651 [inline]
 tty_ldisc_release+0xe8/0x400 drivers/tty/tty_ldisc.c:818
 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1603
 tty_release+0xb3f/0x10d0 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x417b71
RSP: 002b:00007ffde5350230 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000417b71
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000004
RBP: 0000000000000001 R08: 00000000000002a1 R09: 00000000a2ca82a5
R10: 00007ffde5350310 R11: 0000000000000293 R12: 000000000119ca00
R13: 000000000119ca00 R14: 00000000000003e8 R15: 000000000119bf8c
Code: 15 3a f7 ff eb d2 0f 1f 00 55 48 89 fd 48 83 ec 08 e8 83 4d cd ff 48 8d 7d 64 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 4f 
RIP: cdev_del+0x22/0x90 fs/char_dev.c:602 RSP: ffff8880a197fca0
---[ end trace f49258339090e511 ]---