======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc7-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.1/22991 just changed the state of lock: ffff888038cd0018 (&new->fa_lock){.+..}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1012 [inline] ffff888038cd0018 (&new->fa_lock){.+..}-{2:2}, at: kill_fasync+0x13b/0x430 fs/fcntl.c:1033 but this lock was taken by another, HARDIRQ-safe lock in the past: (&timer->lock){-.-.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&new->fa_lock); local_irq_disable(); lock(&timer->lock); lock(&new->fa_lock); lock(&timer->lock); *** DEADLOCK *** 5 locks held by syz-executor.1/22991: #0: ffff888019aa2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffff8880110790b8 (&buf->lock){+.+.}-{3:3}, at: paste_selection+0x155/0x500 drivers/tty/vt/selection.c:390 #2: ffffffff8cddb628 (vc_sel.lock){+.+.}-{3:3}, at: paste_selection+0x17b/0x500 drivers/tty/vt/selection.c:393 #3: ffff888019aa22e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_receive_buf_common+0x8e/0x81a0 drivers/tty/n_tty.c:1637 #4: ffffffff8c717ec0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266 the shortest dependencies between 2nd lock and 1st lock: -> (&timer->lock){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] snd_hrtimer_callback+0x51/0x360 sound/core/hrtimer.c:38 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 IN-SOFTIRQ-W at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] snd_hrtimer_callback+0x51/0x360 sound/core/hrtimer.c:38 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 check_kcov_mode kernel/kcov.c:163 [inline] write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_cmp8+0x29/0x90 kernel/kcov.c:264 __phys_addr+0x47/0x160 arch/x86/mm/physaddr.c:28 virt_to_head_page include/linux/mm.h:899 [inline] kmem_cache_free+0x38/0x170 mm/slub.c:3229 rcu_do_batch kernel/rcu/tree.c:2550 [inline] rcu_core+0x906/0x14b0 kernel/rcu/tree.c:2785 __do_softirq+0x372/0x783 kernel/softirq.c:558 run_ksoftirqd+0xa2/0x100 kernel/softirq.c:920 smpboot_thread_fn+0x533/0x9d0 kernel/smpboot.c:164 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [inline] snd_timer_close_locked+0x5c/0x8e0 sound/core/timer.c:396 snd_timer_close+0xaa/0x120 sound/core/timer.c:463 snd_seq_timer_close+0x9b/0xd0 sound/core/seq/seq_timer.c:326 queue_delete sound/core/seq/seq_queue.c:134 [inline] snd_seq_queue_delete+0x8b/0xf0 sound/core/seq/seq_queue.c:196 delete_seq_queue sound/core/seq/oss/seq_oss_init.c:377 [inline] snd_seq_oss_release+0x1ca/0x300 sound/core/seq/oss/seq_oss_init.c:422 odev_release+0x52/0x70 sound/core/seq/oss/seq_oss.c:144 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] snd_timer_new.__key+0x0/0x40 ... acquired at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&new->fa_lock){.+..}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 __receive_buf drivers/tty/n_tty.c:1591 [inline] n_tty_receive_buf_common+0x10dc/0x81a0 drivers/tty/n_tty.c:1674 paste_selection+0x36d/0x500 drivers/tty/vt/selection.c:408 vt_ioctl+0x455/0x37b0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xf51/0x1720 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:311 fasync_remove_entry+0xff/0x1d0 fs/fcntl.c:890 __fput+0x65b/0x7b0 fs/file_table.c:277 task_work_run+0x146/0x1c0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] fasync_insert_entry.__key+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4494 [inline] __lock_acquire+0xcea/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 __receive_buf drivers/tty/n_tty.c:1591 [inline] n_tty_receive_buf_common+0x10dc/0x81a0 drivers/tty/n_tty.c:1674 paste_selection+0x36d/0x500 drivers/tty/vt/selection.c:408 vt_ioctl+0x455/0x37b0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xf51/0x1720 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae stack backtrace: CPU: 1 PID: 22991 Comm: syz-executor.1 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 print_irq_inversion_bug+0xa58/0xda0 kernel/locking/lockdep.c:4000 check_usage_backwards kernel/locking/lockdep.c:2585 [inline] mark_lock_irq kernel/locking/lockdep.c:4156 [inline] mark_lock+0x110b/0x1eb0 kernel/locking/lockdep.c:4593 mark_usage kernel/locking/lockdep.c:4494 [inline] __lock_acquire+0xcea/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 __receive_buf drivers/tty/n_tty.c:1591 [inline] n_tty_receive_buf_common+0x10dc/0x81a0 drivers/tty/n_tty.c:1674 paste_selection+0x36d/0x500 drivers/tty/vt/selection.c:408 vt_ioctl+0x455/0x37b0 drivers/tty/vt/vt_ioctl.c:760 tty_ioctl+0xf51/0x1720 drivers/tty/tty_io.c:2805 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f08f3de0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000020000100 RSI: 000000000000541c RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffea4e71bef R14: 00007f08f3de0300 R15: 0000000000022000