======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc7-syzkaller #0 Not tainted -------------------------------------------------------- kworker/u4:16/17853 just changed the state of lock: ffff8881479e8108 (&group->lock){..-.}-{2:2}, at: snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (&new->fa_lock){.+.+}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &group->lock --> &timer->lock --> &new->fa_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&new->fa_lock); local_irq_disable(); lock(&group->lock); lock(&timer->lock); lock(&group->lock); *** DEADLOCK *** 2 locks held by kworker/u4:16/17853: #0: ffff888029030938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2249 #1: ffffc9000992fd20 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2251 the shortest dependencies between 2nd lock and 1st lock: -> (&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 fsnotify_add_event+0x35a/0x410 fs/notify/notification.c:128 inotify_handle_inode_event+0x389/0x500 fs/notify/inotify/inotify_fsnotify.c:119 inotify_ignored_and_remove_idr+0x25/0x70 fs/notify/inotify/inotify_user.c:504 fsnotify_destroy_marks+0x148/0x560 fs/notify/mark.c:788 fsnotify_inoderemove include/linux/fsnotify.h:179 [inline] dentry_unlink_inode+0x249/0x3a0 fs/dcache.c:372 vfs_rmdir+0x1cb/0x3f0 fs/namei.c:3919 do_rmdir+0x368/0x680 fs/namei.c:3968 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 SOFTIRQ-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 fsnotify_add_event+0x35a/0x410 fs/notify/notification.c:128 inotify_handle_inode_event+0x389/0x500 fs/notify/inotify/inotify_fsnotify.c:119 inotify_ignored_and_remove_idr+0x25/0x70 fs/notify/inotify/inotify_user.c:504 fsnotify_destroy_marks+0x148/0x560 fs/notify/mark.c:788 fsnotify_inoderemove include/linux/fsnotify.h:179 [inline] dentry_unlink_inode+0x249/0x3a0 fs/dcache.c:372 vfs_rmdir+0x1cb/0x3f0 fs/namei.c:3919 do_rmdir+0x368/0x680 fs/namei.c:3968 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 fsnotify_fasync+0x4d/0x70 fs/notify/group.c:162 __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 fsnotify_add_event+0x35a/0x410 fs/notify/notification.c:128 inotify_handle_inode_event+0x389/0x500 fs/notify/inotify/inotify_fsnotify.c:119 inotify_ignored_and_remove_idr+0x25/0x70 fs/notify/inotify/inotify_user.c:504 fsnotify_destroy_marks+0x148/0x560 fs/notify/mark.c:788 fsnotify_inoderemove include/linux/fsnotify.h:179 [inline] dentry_unlink_inode+0x249/0x3a0 fs/dcache.c:372 vfs_rmdir+0x1cb/0x3f0 fs/namei.c:3919 do_rmdir+0x368/0x680 fs/namei.c:3968 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: 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 -> (&timer->lock){....}-{2:2} { 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_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_notify+0x105/0x3e0 sound/core/timer.c:1087 snd_pcm_timer_notify sound/core/pcm_native.c:590 [inline] snd_pcm_post_stop sound/core/pcm_native.c:1448 [inline] snd_pcm_action_single sound/core/pcm_native.c:1224 [inline] snd_pcm_action sound/core/pcm_native.c:1305 [inline] snd_pcm_stop+0x3b8/0x4c0 sound/core/pcm_native.c:1471 snd_pcm_drop+0x16d/0x290 sound/core/pcm_native.c:2150 snd_pcm_oss_sync+0x4f4/0xee0 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x72b/0x2510 kernel/exit.c:825 do_group_exit+0x168/0x2d0 kernel/exit.c:922 get_signal+0x16b0/0x2080 kernel/signal.c:2808 arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x191/0x220 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 -> (&group->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_release+0x543/0x7b0 kernel/locking/lockdep.c:5649 rcu_read_unlock include/linux/rcupdate.h:720 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x251/0x5b0 net/batman-adv/network-coding.c:715 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 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_pcm_group_lock_irq sound/core/pcm_native.c:97 [inline] snd_pcm_stream_lock_irq sound/core/pcm_native.c:136 [inline] snd_pcm_hw_params+0xca/0x1740 sound/core/pcm_native.c:681 snd_pcm_oss_change_params_locked+0x245a/0x4390 sound/core/oss/pcm_oss.c:947 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1091 [inline] snd_pcm_oss_make_ready sound/core/oss/pcm_oss.c:1150 [inline] snd_pcm_oss_sync+0x587/0xee0 sound/core/oss/pcm_oss.c:1650 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 task_work_run+0x146/0x1c0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x72b/0x2510 kernel/exit.c:825 do_group_exit+0x168/0x2d0 kernel/exit.c:922 get_signal+0x16b0/0x2080 kernel/signal.c:2808 arch_do_signal_or_restart+0x8e/0x6d0 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x191/0x220 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_pcm_group_init.__key+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0xca1/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_release+0x543/0x7b0 kernel/locking/lockdep.c:5649 rcu_read_unlock include/linux/rcupdate.h:720 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x251/0x5b0 net/batman-adv/network-coding.c:715 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 stack backtrace: CPU: 1 PID: 17853 Comm: kworker/u4:16 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker 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_forwards kernel/locking/lockdep.c:2585 [inline] mark_lock_irq kernel/locking/lockdep.c:4163 [inline] mark_lock+0x1064/0x1eb0 kernel/locking/lockdep.c:4593 mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0xca1/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_release+0x543/0x7b0 kernel/locking/lockdep.c:5649 Code: 3c 38 00 74 08 48 89 df e8 ba 08 67 00 f6 84 24 91 00 00 00 02 75 68 41 f7 c4 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 37 00 00 00 00 4b c7 44 37 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000992fac0 EFLAGS: 00000206 RAX: 1ffff92001325f6a RBX: ffffc9000992fb50 RCX: 000000000992fb03 RDX: 1ffff92001325f68 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000992fbe8 R08: dffffc0000000000 R09: fffffbfff1b74ee6 R10: fffffbfff1b74ee6 R11: 0000000000000000 R12: 0000000000000246 R13: ffff88807a065f00 R14: 1ffff92001325f64 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:720 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x251/0x5b0 net/batman-adv/network-coding.c:715 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 3c 38 cmp $0x38,%al 2: 00 74 08 48 add %dh,0x48(%rax,%rcx,1) 6: 89 df mov %ebx,%edi 8: e8 ba 08 67 00 callq 0x6708c7 d: f6 84 24 91 00 00 00 testb $0x2,0x91(%rsp) 14: 02 15: 75 68 jne 0x7f 17: 41 f7 c4 00 02 00 00 test $0x200,%r12d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 04 37 00 00 00 movq $0x0,(%r15,%r14,1) <-- trapping instruction 31: 00 32: 4b c7 44 37 08 00 00 movq $0x0,0x8(%r15,%r14,1) 39: 00 00 3b: 65 gs 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 04 25 add $0x25,%al