===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected syzkaller #0 Not tainted ----------------------------------------------------- syz.0.3170/17021 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff88804f84e600 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1122 [inline] ffff88804f84e600 (&new->fa_lock){....}-{3:3}, at: kill_fasync fs/fcntl.c:1146 [inline] ffff88804f84e600 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x138/0x510 fs/fcntl.c:1139 and this task is already holding: ffff888029a25028 (&client->buffer_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888029a25028 (&client->buffer_lock){..-.}-{3:3}, at: evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261 which would create a new lock dependency: (&client->buffer_lock){..-.}-{3:3} -> (&new->fa_lock){....}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (&client->buffer_lock){..-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:353 [inline] input_handle_event+0xb29/0x14d0 drivers/input/input.c:370 input_event drivers/input/input.c:396 [inline] input_event+0x8e/0xd0 drivers/input/input.c:391 hidinput_hid_event+0x90b/0x2440 drivers/hid/hid-input.c:1730 hid_process_event+0x4b7/0x5e0 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xa0a/0x1290 drivers/hid/hid-core.c:2074 __hid_input_report.constprop.0+0x33f/0x450 drivers/hid/hid-core.c:2144 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 to a SOFTIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1667 do_wait+0x21d/0x590 kernel/exit.c:1711 kernel_wait+0x9f/0x160 kernel/exit.c:1887 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Chain exists of: &client->buffer_lock --> &new->fa_lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&client->buffer_lock); lock(&new->fa_lock); lock(&client->buffer_lock); *** DEADLOCK *** 7 locks held by syz.0.3170/17021: #0: ffff8880423bc118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x184/0x440 drivers/input/evdev.c:511 #1: ffff888021394230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:585 [inline] #1: ffff888021394230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0x9f/0x3b0 drivers/input/input.c:419 #2: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #2: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #2: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xbb/0x3b0 drivers/input/input.c:420 #3: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #3: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #3: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x80/0x880 drivers/input/input.c:119 #4: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #4: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: evdev_events+0x7b/0x390 drivers/input/evdev.c:298 #5: ffff888029a25028 (&client->buffer_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #5: ffff888029a25028 (&client->buffer_lock){..-.}-{3:3}, at: evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261 #6: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #6: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: kill_fasync fs/fcntl.c:1145 [inline] #6: ffffffff8e3c42e0 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x62/0x510 fs/fcntl.c:1139 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&client->buffer_lock){..-.}-{3:3} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:353 [inline] input_handle_event+0xb29/0x14d0 drivers/input/input.c:370 input_event drivers/input/input.c:396 [inline] input_event+0x8e/0xd0 drivers/input/input.c:391 hidinput_hid_event+0x90b/0x2440 drivers/hid/hid-input.c:1730 hid_process_event+0x4b7/0x5e0 drivers/hid/hid-core.c:1565 hid_process_report drivers/hid/hid-core.c:1713 [inline] hid_report_raw_event+0xa0a/0x1290 drivers/hid/hid-core.c:2074 __hid_input_report.constprop.0+0x33f/0x450 drivers/hid/hid-core.c:2144 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x2e1/0x440 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e } ... key at: [] __key.83+0x0/0x40 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1667 do_wait+0x21d/0x590 kernel/exit.c:1711 kernel_wait+0x9f/0x160 kernel/exit.c:1887 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1667 do_wait+0x21d/0x590 kernel/exit.c:1711 kernel_wait+0x9f/0x160 kernel/exit.c:1887 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 copy_process+0x4fe3/0x76a0 kernel/fork.c:2327 kernel_clone+0xfc/0x930 kernel/fork.c:2609 user_mode_thread+0xc8/0x110 kernel/fork.c:2685 rest_init+0x23/0x2b0 init/main.c:722 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 __do_wait+0x105/0x890 kernel/exit.c:1667 do_wait+0x21d/0x590 kernel/exit.c:1711 kernel_wait+0x9f/0x160 kernel/exit.c:1887 call_usermodehelper_exec_sync kernel/umh.c:136 [inline] call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 send_sigurg+0xed/0xc80 fs/fcntl.c:965 sk_send_sigurg+0x76/0x360 net/core/sock.c:3609 queue_oob net/unix/af_unix.c:2380 [inline] unix_stream_sendmsg+0xfa5/0x1340 net/unix/af_unix.c:2516 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmmsg+0x2f9/0x420 net/socket.c:2766 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0x9d/0x100 net/compat.c:364 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> (&f_owner->lock){....}-{3:3} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 __f_setown+0x61/0x3c0 fs/fcntl.c:136 __tty_fasync+0x1bf/0x300 drivers/tty/tty_io.c:2237 tty_fasync+0x9e/0xe0 drivers/tty/tty_io.c:2252 ioctl_fioasync fs/ioctl.c:378 [inline] do_vfs_ioctl+0xa08/0x14f0 fs/ioctl.c:511 __do_compat_sys_ioctl fs/ioctl.c:689 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x1c0/0x370 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 send_sigio+0x31/0x3e0 fs/fcntl.c:905 kill_fasync_rcu fs/fcntl.c:1131 [inline] kill_fasync fs/fcntl.c:1146 [inline] kill_fasync+0x214/0x510 fs/fcntl.c:1139 __receive_buf drivers/tty/n_tty.c:1640 [inline] n_tty_receive_buf_common+0x5d1/0x1980 drivers/tty/n_tty.c:1723 tty_ldisc_receive_buf+0xaa/0x1a0 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x26b/0x730 drivers/tty/tty_buffer.c:495 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] __key.1+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 send_sigio+0x31/0x3e0 fs/fcntl.c:905 kill_fasync_rcu fs/fcntl.c:1131 [inline] kill_fasync fs/fcntl.c:1146 [inline] kill_fasync+0x214/0x510 fs/fcntl.c:1139 __receive_buf drivers/tty/n_tty.c:1640 [inline] n_tty_receive_buf_common+0x5d1/0x1980 drivers/tty/n_tty.c:1723 tty_ldisc_receive_buf+0xaa/0x1a0 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x26b/0x730 drivers/tty/tty_buffer.c:495 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> (&new->fa_lock){....}-{3:3} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 fasync_remove_entry+0xb2/0x1e0 fs/fcntl.c:999 fasync_helper+0xaf/0xd0 fs/fcntl.c:1102 __tty_fasync+0x1e4/0x300 drivers/tty/tty_io.c:2219 tty_fasync+0x9e/0xe0 drivers/tty/tty_io.c:2252 __fput+0x96b/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:966 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] __do_fast_syscall_32+0x240/0x300 arch/x86/entry/syscall_32.c:309 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1122 [inline] kill_fasync fs/fcntl.c:1146 [inline] kill_fasync+0x138/0x510 fs/fcntl.c:1139 __receive_buf drivers/tty/n_tty.c:1640 [inline] n_tty_receive_buf_common+0x5d1/0x1980 drivers/tty/n_tty.c:1723 tty_ldisc_receive_buf+0xaa/0x1a0 drivers/tty/tty_buffer.c:387 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x26b/0x730 drivers/tty/tty_buffer.c:495 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 } ... key at: [] __key.0+0x0/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1122 [inline] kill_fasync fs/fcntl.c:1146 [inline] kill_fasync+0x138/0x510 fs/fcntl.c:1139 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x619/0x9b0 drivers/input/evdev.c:278 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x2e1/0x440 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e stack backtrace: CPU: 0 UID: 0 PID: 17021 Comm: syz.0.3170 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline] check_irq_usage+0x7dc/0x920 kernel/locking/lockdep.c:2857 check_prev_add kernel/locking/lockdep.c:3169 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1285/0x1c90 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:1122 [inline] kill_fasync fs/fcntl.c:1146 [inline] kill_fasync+0x138/0x510 fs/fcntl.c:1139 __pass_event drivers/input/evdev.c:240 [inline] evdev_pass_values+0x619/0x9b0 drivers/input/evdev.c:278 evdev_events+0x1bb/0x390 drivers/input/evdev.c:306 input_pass_values+0x74e/0x880 drivers/input/input.c:128 input_event_dispose drivers/input/input.c:342 [inline] input_handle_event+0xf00/0x14d0 drivers/input/input.c:370 input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424 evdev_write+0x2e1/0x440 drivers/input/evdev.c:528 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f43579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f543655c EFLAGS: 00000296 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 000000000000000c RCX: 0000000080000040 RDX: 0000000000001068 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi