BUG: sleeping function called from invalid context at drivers/tty/vt/vt.c:2245 in_atomic(): 1, irqs_disabled(): 1, pid: 14206, name: syz-executor.4 3 locks held by syz-executor.4/14206: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&(&gsm->control_lock)->rlock){....}, at: [] gsm_control_send+0xf6/0x480 drivers/tty/n_gsm.c:1434 #2: (&(&gsm->tx_lock)->rlock){....}, at: [] gsm_data_queue drivers/tty/n_gsm.c:845 [inline] #2: (&(&gsm->tx_lock)->rlock){....}, at: [] gsm_control_transmit+0x1f1/0x2d0 drivers/tty/n_gsm.c:1375 irq event stamp: 28 hardirqs last enabled at (27): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (27): [] _raw_spin_unlock_irqrestore+0x79/0xe0 kernel/locking/spinlock.c:192 hardirqs last disabled at (28): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (28): [] _raw_spin_lock_irqsave+0x66/0xc0 kernel/locking/spinlock.c:160 softirqs last enabled at (0): [] copy_process.part.0+0x12d0/0x71c0 kernel/fork.c:1734 softirqs last disabled at (0): [< (null)>] (null) Preemption disabled at: [< (null)>] (null) CPU: 1 PID: 14206 Comm: syz-executor.4 Not tainted 4.14.304-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 ___might_sleep.cold+0x235/0x250 kernel/sched/core.c:6041 do_con_write+0xd0/0x19b0 drivers/tty/vt/vt.c:2245 con_write+0x21/0xa0 drivers/tty/vt/vt.c:2822 gsmld_output+0xc3/0x190 drivers/tty/n_gsm.c:2312 gsm_data_kick+0x266/0x9b0 drivers/tty/n_gsm.c:761 gsm_data_queue drivers/tty/n_gsm.c:846 [inline] gsm_control_transmit+0x1ff/0x2d0 drivers/tty/n_gsm.c:1375 gsm_control_send+0x38a/0x480 drivers/tty/n_gsm.c:1451 gsm_disconnect drivers/tty/n_gsm.c:2110 [inline] gsmld_config.constprop.0+0x568/0xf90 drivers/tty/n_gsm.c:2636 gsmld_ioctl+0x375/0x410 drivers/tty/n_gsm.c:2700 tty_ioctl+0x5af/0x1430 drivers/tty/tty_io.c:2670 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7fb88c66a0c9 RSP: 002b:00007fb88abbb168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb88c78a050 RCX: 00007fb88c66a0c9 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000003 RBP: 00007fb88c6c5ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd5125085f R14: 00007fb88abbb300 R15: 0000000000022000 ======================================================== WARNING: possible irq lock inversion dependency detected 4.14.304-syzkaller #0 Tainted: G W -------------------------------------------------------- ksoftirqd/1/17 just changed the state of lock: (&(&gsm->control_lock)->rlock){..-.}, at: [] gsm_control_retransmit+0x25/0x2c0 drivers/tty/n_gsm.c:1394 but this lock took another, SOFTIRQ-unsafe lock in the past: (console_lock){+.+.} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &(&gsm->control_lock)->rlock --> &(&gsm->tx_lock)->rlock --> console_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(console_lock); local_irq_disable(); lock(&(&gsm->control_lock)->rlock); lock(&(&gsm->tx_lock)->rlock); lock(&(&gsm->control_lock)->rlock); *** DEADLOCK *** 1 lock held by ksoftirqd/1/17: #0: (((&gsm->t2_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #0: (((&gsm->t2_timer))){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1270 the shortest dependencies between 2nd lock and 1st lock: -> (console_lock){+.+.} ops: 4822 { HARDIRQ-ON-W at: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_lock+0x42/0x70 kernel/printk/printk.c:2228 con_init+0x12/0x5d6 drivers/tty/vt/vt.c:3022 console_init+0x46/0x53 kernel/printk/printk.c:2809 start_kernel+0x521/0x763 init/main.c:638 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 SOFTIRQ-ON-W at: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_lock+0x42/0x70 kernel/printk/printk.c:2228 con_init+0x12/0x5d6 drivers/tty/vt/vt.c:3022 console_init+0x46/0x53 kernel/printk/printk.c:2809 start_kernel+0x521/0x763 init/main.c:638 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 INITIAL USE at: } ... key at: [] console_lock_dep_map+0x0/0x40 BUG: scheduling while atomic: syz-executor.3/14222/0x00000003 ... acquired at: console_lock+0x42/0x70 kernel/printk/printk.c:2228 do_con_write+0xd5/0x19b0 drivers/tty/vt/vt.c:2247 INFO: lockdep is turned off. con_write+0x21/0xa0 drivers/tty/vt/vt.c:2822 Modules linked in: gsmld_output+0xc3/0x190 drivers/tty/n_gsm.c:2312 gsm_data_kick+0x266/0x9b0 drivers/tty/n_gsm.c:761 gsm_data_queue drivers/tty/n_gsm.c:846 [inline] gsm_control_transmit+0x1ff/0x2d0 drivers/tty/n_gsm.c:1375 gsm_control_send+0x38a/0x480 drivers/tty/n_gsm.c:1451 gsm_disconnect drivers/tty/n_gsm.c:2110 [inline] gsmld_config.constprop.0+0x568/0xf90 drivers/tty/n_gsm.c:2636 gsmld_ioctl+0x375/0x410 drivers/tty/n_gsm.c:2700 tty_ioctl+0x5af/0x1430 drivers/tty/tty_io.c:2670 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 Preemption disabled at: do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 [< (null)>] (null) entry_SYSCALL_64_after_hwframe+0x5e/0xd3 -> (&(&gsm->tx_lock)->rlock){....} ops: 1 { INITIAL USE at: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 gsm_data_queue drivers/tty/n_gsm.c:845 [inline] gsm_control_transmit+0x1f1/0x2d0 drivers/tty/n_gsm.c:1375 gsm_control_send+0x38a/0x480 drivers/tty/n_gsm.c:1451 gsm_disconnect drivers/tty/n_gsm.c:2110 [inline] gsmld_config.constprop.0+0x568/0xf90 drivers/tty/n_gsm.c:2636 gsmld_ioctl+0x375/0x410 drivers/tty/n_gsm.c:2700 tty_ioctl+0x5af/0x1430 drivers/tty/tty_io.c:2670