BUG: sleeping function called from invalid context at drivers/tty/vt/vt.c:2245 in_atomic(): 1, irqs_disabled(): 1, pid: 7969, name: syz-executor131 3 locks held by syz-executor131/7969: #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: 13078 hardirqs last enabled at (13077): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (13077): [] _raw_spin_unlock_irqrestore+0x79/0xe0 kernel/locking/spinlock.c:192 hardirqs last disabled at (13078): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (13078): [] _raw_spin_lock_irqsave+0x66/0xc0 kernel/locking/spinlock.c:160 softirqs last enabled at (12826): [] __do_softirq+0x68b/0x9ff kernel/softirq.c:314 softirqs last disabled at (12689): [] invoke_softirq kernel/softirq.c:368 [inline] softirqs last disabled at (12689): [] irq_exit+0x193/0x240 kernel/softirq.c:409 Preemption disabled at: [< (null)>] (null) CPU: 0 PID: 7969 Comm: syz-executor131 Not tainted 4.14.294-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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+0x46/0xbb RIP: 0033:0x7fe49c3b4319 RSP: 002b:00007ffc6afdbc38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe49c3b4319 RDX: 0000000020000040 RSI: 00000000404c4701 RDI: 0000000000000003 RBP: 00007fe49c3781a0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000e R11: 0000000000000246 R12: 00007fe49c378230 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ======================================================== WARNING: possible irq lock inversion dependency detected 4.14.294-syzkaller #0 Tainted: G W -------------------------------------------------------- swapper/0/0 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 swapper/0/0: #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: 2761 { 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 ... acquired at: console_lock+0x42/0x70 kernel/printk/printk.c:2228 do_con_write+0xd5/0x19b0 drivers/tty/vt/vt.c:2247 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+0x46/0xbb -> (&(&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 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+0x46/0xbb } ... key at: [] __key.4+0x0/0x40 ... acquired at: __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 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+0x46/0xbb -> (&(&gsm->control_lock)->rlock){..-.} ops: 2 { IN-SOFTIRQ-W 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_control_retransmit+0x25/0x2c0 drivers/tty/n_gsm.c:1394 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:558 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x743/0x763 init/main.c:712 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 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_control_send+0xf6/0x480 drivers/tty/n_gsm.c:1434 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+0x46/0xbb } ... key at: [] __key.5+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:2804 [inline] mark_lock+0x3c7/0x1050 kernel/locking/lockdep.c:3194 mark_irqflags kernel/locking/lockdep.c:3072 [inline] __lock_acquire+0xc81/0x3f20 kernel/locking/lockdep.c:3448 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_control_retransmit+0x25/0x2c0 drivers/tty/n_gsm.c:1394 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:558 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x743/0x763 init/main.c:712 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.14.294-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_irq_inversion_bug.cold+0x313/0x346 kernel/locking/lockdep.c:2670 check_usage_forwards+0x18f/0x2d0 kernel/locking/lockdep.c:2695 mark_lock_irq kernel/locking/lockdep.c:2804 [inline] mark_lock+0x3c7/0x1050 kernel/locking/lockdep.c:3194 mark_irqflags kernel/locking/lockdep.c:3072 [inline] __lock_acquire+0xc81/0x3f20 kernel/locking/lockdep.c:3448 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_control_retransmit+0x25/0x2c0 drivers/tty/n_gsm.c:1394 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 RSP: 0018:ffffffff88e07e78 EFLAGS: 000002c2 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff11e135c RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff88e74d04 RBP: ffffffff88f09ad0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff11ce890 R13: ffffffff88e74480 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:558 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x743/0x763 init/main.c:712 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240