[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.212' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 27.255087] BUG: sleeping function called from invalid context at drivers/tty/vt/vt.c:2245 [ 27.263610] in_atomic(): 1, irqs_disabled(): 1, pid: 7965, name: syz-executor119 [ 27.271139] 3 locks held by syz-executor119/7965: [ 27.276064] #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 [ 27.284976] #1: (&(&tty->flow_lock)->rlock){....}, at: [] n_tty_ioctl_helper+0xa0/0x350 [ 27.294842] #2: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref+0x1b/0x80 [ 27.303324] irq event stamp: 6986 [ 27.306755] hardirqs last enabled at (6985): [] _raw_spin_unlock_irqrestore+0x79/0xe0 [ 27.316357] hardirqs last disabled at (6986): [] _raw_spin_lock_irq+0x35/0x80 [ 27.325254] softirqs last enabled at (5506): [] __do_softirq+0x68b/0x9ff [ 27.333977] softirqs last disabled at (5481): [] irq_exit+0x193/0x240 [ 27.342102] Preemption disabled at: [ 27.342106] [< (null)>] (null) [ 27.350518] CPU: 1 PID: 7965 Comm: syz-executor119 Not tainted 4.14.290-syzkaller #0 [ 27.358369] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 [ 27.367708] Call Trace: [ 27.370276] dump_stack+0x1b2/0x281 [ 27.373879] ___might_sleep.cold+0x235/0x250 [ 27.378264] do_con_write+0xd0/0x19b0 [ 27.382041] ? resched_curr+0xc7/0x360 [ 27.385913] ? n_hdlc_buf_get+0x194/0x220 [ 27.390036] ? lock_acquire+0x170/0x3f0 [ 27.393983] ? lock_downgrade+0x740/0x740 [ 27.398112] ? do_con_trol+0x51e0/0x51e0 [ 27.402150] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 27.407229] con_write+0x21/0xa0 [ 27.410568] ? con_put_char+0xa0/0xa0 [ 27.414343] n_hdlc_send_frames+0x241/0x410 [ 27.418659] n_hdlc_tty_wakeup+0x95/0xb0 [ 27.422694] ? n_hdlc_tty_open+0x4d0/0x4d0 [ 27.427001] tty_wakeup+0xc3/0xf0 [ 27.430429] ? insert_char+0x280/0x280 [ 27.434309] __start_tty+0x10b/0x140 [ 27.438001] n_tty_ioctl_helper+0x2f8/0x350 [ 27.442296] n_hdlc_tty_ioctl+0xd4/0x300 [ 27.446333] tty_ioctl+0x5af/0x1430 [ 27.449950] ? n_hdlc_tty_wakeup+0xb0/0xb0 [ 27.454159] ? tty_fasync+0x2c0/0x2c0 [ 27.457929] ? tty_write+0x4a3/0x740 [ 27.461617] ? n_hdlc_tty_poll+0x300/0x300 [ 27.465841] ? fsnotify+0x974/0x11b0 [ 27.469545] ? tty_compat_ioctl+0x240/0x240 [ 27.473973] ? __handle_mm_fault+0x80f/0x4620 [ 27.478450] ? tty_fasync+0x2c0/0x2c0 [ 27.482224] do_vfs_ioctl+0x75a/0xff0 [ 27.486001] ? ioctl_preallocate+0x1a0/0x1a0 [ 27.490386] ? rw_verify_area+0xe1/0x2a0 [ 27.494424] ? vfs_write+0x319/0x4d0 [ 27.498115] ? SyS_write+0x14d/0x210 [ 27.501804] ? security_file_ioctl+0x83/0xb0 [ 27.506186] SyS_ioctl+0x7f/0xb0 [ 27.509544] ? do_vfs_ioctl+0xff0/0xff0 [ 27.513503] do_syscall_64+0x1d5/0x640 [ 27.517390] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.522551] RIP: 0033:0x7fcaea2652e9 [ 27.526238] RSP: 002b:00007ffc74a45be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 27.533922] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcaea2652e9 [ 27.541178] RDX: 0000000000000001 RSI: 000000000000540a RDI: 0000000000000003 [ 27.548422] RBP: 00007fcaea229170 R08: 0000000000000000 R09: 0000000000000000 [ 27.555