===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.18.0-rc4-syzkaller-00006-gd615b5416f8a #0 Not tainted ----------------------------------------------------- syz-executor.4/6926 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff8880798b6558 (&new->fa_lock){....}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:996 [inline] ffff8880798b6558 (&new->fa_lock){....}-{2:2}, at: kill_fasync fs/fcntl.c:1017 [inline] ffff8880798b6558 (&new->fa_lock){....}-{2:2}, at: kill_fasync+0x136/0x470 fs/fcntl.c:1010 and this task is already holding: ffff888022a6a148 (&timer->lock){..-.}-{2:2}, at: snd_timer_start1+0x5a/0x800 sound/core/timer.c:541 which would create a new lock dependency: (&timer->lock){..-.}-{2:2} -> (&new->fa_lock){....}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (&timer->lock){..-.}-{2:2} ... which became SOFTIRQ-irq-safe at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:856 snd_timer_interrupt sound/core/timer.c:1154 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1154 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 to a SOFTIRQ-irq-unsafe lock: (tasklist_lock){.+.+}-{2:2} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1508 kernel_wait+0x9c/0x150 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 other info that might help us debug this: Chain exists of: &timer->lock --> &new->fa_lock --> tasklist_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(&timer->lock); lock(&new->fa_lock); lock(&timer->lock); *** DEADLOCK *** 3 locks held by syz-executor.4/6926: #0: ffff888070df4168 (&tu->ioctl_lock){+.+.}-{3:3}, at: snd_timer_user_ioctl+0x4c/0xb0 sound/core/timer.c:2127 #1: ffff888022a6a148 (&timer->lock){..-.}-{2:2}, at: snd_timer_start1+0x5a/0x800 sound/core/timer.c:541 #2: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x41/0x470 fs/fcntl.c:1015 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&timer->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:856 snd_timer_interrupt sound/core/timer.c:1154 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1154 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:645 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 snd_timer_notify sound/core/timer.c:1086 [inline] snd_timer_notify+0x10c/0x3d0 sound/core/timer.c:1073 snd_pcm_timer_notify sound/core/pcm_native.c:608 [inline] snd_pcm_post_start+0x24a/0x310 sound/core/pcm_native.c:1451 snd_pcm_action_single+0xf4/0x130 sound/core/pcm_native.c:1283 snd_pcm_action+0x6e/0x90 sound/core/pcm_native.c:1364 __snd_pcm_lib_xfer+0x179c/0x1e10 sound/core/pcm_lib.c:2238 snd_pcm_oss_read3+0x1c4/0x400 sound/core/oss/pcm_oss.c:1292 io_capture_transfer+0x27e/0x330 sound/core/oss/io.c:73 snd_pcm_plug_read_transfer+0x1a4/0x2e0 sound/core/oss/pcm_plugin.c:663 snd_pcm_oss_read2+0x1db/0x3f0 sound/core/oss/pcm_oss.c:1493 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1550 [inline] snd_pcm_oss_read+0x620/0x7a0 sound/core/oss/pcm_oss.c:2788 vfs_read+0x1ef/0x5d0 fs/read_write.c:480 ksys_read+0x127/0x250 fs/read_write.c:620 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.10+0x0/0x40 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (tasklist_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1508 kernel_wait+0x9c/0x150 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1508 kernel_wait+0x9c/0x150 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:326 copy_process+0x4364/0x6fe0 kernel/fork.c:2368 kernel_clone+0xe7/0xab0 kernel/fork.c:2639 kernel_thread+0xb5/0xf0 kernel/fork.c:2691 rest_init+0x23/0x3e0 init/main.c:691 start_kernel+0x47f/0x4a0 init/main.c:1140 secondary_startup_64_no_verify+0xc3/0xcb INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 do_wait+0x284/0xce0 kernel/exit.c:1508 kernel_wait+0x9c/0x150 kernel/exit.c:1698 call_usermodehelper_exec_sync kernel/umh.c:139 [inline] call_usermodehelper_exec_work+0xf5/0x180 kernel/umh.c:166 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 } ... key at: [] tasklist_lock+0x18/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:228 send_sigio+0xab/0x380 fs/fcntl.c:792 kill_fasync_rcu fs/fcntl.c:1003 [inline] kill_fasync fs/fcntl.c:1017 [inline] kill_fasync+0x1f8/0x470 fs/fcntl.c:1010 lease_break_callback+0x1f/0x30 fs/locks.c:507 __break_lease+0x3d7/0x1420 fs/locks.c:1480 break_lease include/linux/fs.h:2506 [inline] break_lease include/linux/fs.h:2496 [inline] do_dentry_open+0x432/0x11e0 fs/open.c:815 do_open fs/namei.c:3476 [inline] path_openat+0x1c71/0x2910 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4c0 fs/open.c:1213 do_sys_open fs/open.c:1229 [inline] __do_sys_creat fs/open.c:1305 [inline] __se_sys_creat fs/open.c:1299 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1299 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&f->f_owner.lock){....}-{2:2} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:326 f_modown+0x2a/0x390 fs/fcntl.c:91 fcntl_dirnotify+0x7c9/0xbc0 fs/notify/dnotify/dnotify.c:369 do_fcntl+0x24c/0x10b0 fs/fcntl.c:406 __do_sys_fcntl fs/fcntl.c:454 [inline] __se_sys_fcntl fs/fcntl.c:439 [inline] __x64_sys_fcntl+0x15f/0x1d0 fs/fcntl.c:439 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock_irq include/linux/rwlock_api_smp.h:169 [inline] _raw_read_lock_irq+0x63/0x80 kernel/locking/spinlock.c:244 f_getown_ex fs/fcntl.c:212 [inline] do_fcntl+0x8ae/0x10b0 fs/fcntl.c:380 __do_sys_fcntl fs/fcntl.c:454 [inline] __se_sys_fcntl fs/fcntl.c:439 [inline] __x64_sys_fcntl+0x15f/0x1d0 fs/fcntl.c:439 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.5+0x0/0x40 ... acquired at: __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236 send_sigio+0x24/0x380 fs/fcntl.c:778 kill_fasync_rcu fs/fcntl.c:1003 [inline] kill_fasync fs/fcntl.c:1017 [inline] kill_fasync+0x1f8/0x470 fs/fcntl.c:1010 lease_break_callback+0x1f/0x30 fs/locks.c:507 __break_lease+0x3d7/0x1420 fs/locks.c:1480 break_lease include/linux/fs.h:2506 [inline] break_lease include/linux/fs.h:2496 [inline] do_dentry_open+0x432/0x11e0 fs/open.c:815 do_open fs/namei.c:3476 [inline] path_openat+0x1c71/0x2910 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4c0 fs/open.c:1213 do_sys_open fs/open.c:1229 [inline] __do_sys_creat fs/open.c:1305 [inline] __se_sys_creat fs/open.c:1299 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1299 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&new->fa_lock){....}-{2:2} { INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:326 fasync_remove_entry+0xb6/0x1e0 fs/fcntl.c:873 fasync_helper+0x9e/0xb0 fs/fcntl.c:976 sock_fasync+0x94/0x140 net/socket.c:1343 __fput+0x834/0x9d0 fs/file_table.c:314 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:996 [inline] kill_fasync fs/fcntl.c:1017 [inline] kill_fasync+0x136/0x470 fs/fcntl.c:1010 lease_break_callback+0x1f/0x30 fs/locks.c:507 __break_lease+0x3d7/0x1420 fs/locks.c:1480 break_lease include/linux/fs.h:2506 [inline] break_lease include/linux/fs.h:2496 [inline] do_dentry_open+0x432/0x11e0 fs/open.c:815 do_open fs/namei.c:3476 [inline] path_openat+0x1c71/0x2910 fs/namei.c:3609 do_filp_open+0x1aa/0x400 fs/namei.c:3636 do_sys_openat2+0x16d/0x4c0 fs/open.c:1213 do_sys_open fs/open.c:1229 [inline] __do_sys_creat fs/open.c:1305 [inline] __se_sys_creat fs/open.c:1299 [inline] __x64_sys_creat+0xc9/0x120 fs/open.c:1299 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.0+0x0/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:996 [inline] kill_fasync fs/fcntl.c:1017 [inline] kill_fasync+0x136/0x470 fs/fcntl.c:1010 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1386 snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516 snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda4/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae stack backtrace: CPU: 1 PID: 6926 Comm: syz-executor.4 Not tainted 5.18.0-rc4-syzkaller-00006-gd615b5416f8a #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+0xcd/0x134 lib/dump_stack.c:106 print_bad_irq_dependency kernel/locking/lockdep.c:2579 [inline] check_irq_usage.cold+0x4c1/0x6b0 kernel/locking/lockdep.c:2818 check_prev_add kernel/locking/lockdep.c:3069 [inline] check_prevs_add kernel/locking/lockdep.c:3188 [inline] validate_chain kernel/locking/lockdep.c:3803 [inline] __lock_acquire+0x2ade/0x56c0 kernel/locking/lockdep.c:5029 lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x70/0x90 kernel/locking/spinlock.c:236 kill_fasync_rcu fs/fcntl.c:996 [inline] kill_fasync fs/fcntl.c:1017 [inline] kill_fasync+0x136/0x470 fs/fcntl.c:1010 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1386 snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516 snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:696 [inline] snd_timer_start sound/core/timer.c:689 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1984 __snd_timer_user_ioctl.isra.0+0xda4/0x2490 sound/core/timer.c:2107 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2128 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe5894890e9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe5883fe168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe58959bf60 RCX: 00007fe5894890e9 RDX: 0000000000000000 RSI: 00000000000054a0 RDI: 0000000000000003 RBP: 00007fe5894e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe589acfb1f R14: 00007fe5883fe300 R15: 0000000000022000