RBP: 00007ffd5d7933d0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 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: 1 PID: 7041 Comm: syz-executor468 Not tainted 4.14.157-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888093fd2140 task.stack: ffff88807b630000 RIP: 0010:cdev_del+0x28/0xa0 fs/char_dev.c:602 RSP: 0018:ffff88807b637b10 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888218e1e100 RCX: 0000000000000000 RDX: 000000000000000c RSI: ffff888093fd29e8 RDI: 0000000000000064 RBP: ffff88807b637b20 R08: ffff888093fd2140 R09: ffff888093fd2a08 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000008 R14: ffff888218e50ac8 R15: ffff888089959728 FS: 0000000000fee880(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f406a72c000 CR3: 00000000a680b000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_unregister_device drivers/tty/tty_io.c:3041 [inline] tty_unregister_device+0x106/0x1a0 drivers/tty/tty_io.c:3036 gsmld_detach_gsm drivers/tty/n_gsm.c:2299 [inline] gsmld_close+0xb2/0x178 drivers/tty/n_gsm.c:2368 tty_ldisc_close.isra.0+0x99/0xd0 drivers/tty/tty_ldisc.c:498 tty_ldisc_kill+0x4b/0xc0 drivers/tty/tty_ldisc.c:644 tty_ldisc_release+0xb6/0x230 drivers/tty/tty_ldisc.c:811 tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1603 tty_release+0xaa3/0xd60 drivers/tty/tty_io.c:1776 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x7df/0x2ce0 kernel/exit.c:874 do_group_exit+0x111/0x330 kernel/exit.c:977 SYSC_exit_group kernel/exit.c:988 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:986 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x43fdb8 RSP: 002b:00007ffd5d793378 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fdb8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004bfaf0 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 Code: ff eb dd 55 48 89 e5 41 54 49 89 fc 48 83 ec 08 e8 8e ea cc ff 49 8d 7c 24 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 55 RIP: cdev_del+0x28/0xa0 fs/char_dev.c:602 RSP: ffff88807b637b10 ---[ end trace c6470828c66c35dc ]---