===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.14.0-rc6-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.4/26626 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff888035a7e9f0 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync_rcu fs/fcntl.c:1012 [inline] ffff888035a7e9f0 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync fs/fcntl.c:1033 [inline] ffff888035a7e9f0 (&new->fa_lock){.+.+}-{2:2}, at: kill_fasync+0x132/0x460 fs/fcntl.c:1026 and this task is already holding: ffff888147b9f948 (&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:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 snd_timer_interrupt sound/core/timer.c:1155 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 preempt_count arch/x86/include/asm/preempt.h:27 [inline] check_kcov_mode kernel/kcov.c:163 [inline] __sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 get_current arch/x86/include/asm/current.h:15 [inline] need_resched include/linux/sched.h:1999 [inline] copy_pte_range mm/memory.c:1040 [inline] copy_pmd_range mm/memory.c:1156 [inline] copy_pud_range mm/memory.c:1193 [inline] copy_p4d_range mm/memory.c:1217 [inline] copy_page_range+0x10a6/0x4420 mm/memory.c:1290 dup_mmap kernel/fork.c:598 [inline] dup_mm+0x9e7/0x1380 kernel/fork.c:1379 copy_mm kernel/fork.c:1431 [inline] copy_process+0x71ec/0x74d0 kernel/fork.c:2119 kernel_clone+0xe7/0xac0 kernel/fork.c:2509 __do_sys_clone+0xc8/0x110 kernel/fork.c:2626 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 to a SOFTIRQ-irq-unsafe lock: (&new->fa_lock){.+.+}-{2:2} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 pipe_release+0x1ba/0x320 fs/pipe.c:729 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae 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 *** 3 locks held by syz-executor.4/26626: #0: ffff88801be88968 (&tu->ioctl_lock){+.+.}-{3:3}, at: snd_timer_user_ioctl+0x4c/0xb0 sound/core/timer.c:2128 #1: ffff888147b9f948 (&timer->lock){..-.}-{2:2}, at: snd_timer_start1+0x5a/0x800 sound/core/timer.c:541 #2: ffffffff8b979840 (rcu_read_lock){....}-{1:2}, at: kill_fasync+0x3d/0x460 fs/fcntl.c:1031 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:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 snd_timer_interrupt sound/core/timer.c:1155 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 preempt_count arch/x86/include/asm/preempt.h:27 [inline] check_kcov_mode kernel/kcov.c:163 [inline] __sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 get_current arch/x86/include/asm/current.h:15 [inline] need_resched include/linux/sched.h:1999 [inline] copy_pte_range mm/memory.c:1040 [inline] copy_pmd_range mm/memory.c:1156 [inline] copy_pud_range mm/memory.c:1193 [inline] copy_p4d_range mm/memory.c:1217 [inline] copy_page_range+0x10a6/0x4420 mm/memory.c:1290 dup_mmap kernel/fork.c:598 [inline] dup_mm+0x9e7/0x1380 kernel/fork.c:1379 copy_mm kernel/fork.c:1431 [inline] copy_process+0x71ec/0x74d0 kernel/fork.c:2119 kernel_clone+0xe7/0xac0 kernel/fork.c:2509 __do_sys_clone+0xc8/0x110 kernel/fork.c:2626 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 USE at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_notify sound/core/timer.c:1087 [inline] snd_timer_notify+0x10c/0x3d0 sound/core/timer.c:1074 snd_pcm_timer_notify sound/core/pcm_native.c:590 [inline] snd_pcm_post_stop+0x195/0x1f0 sound/core/pcm_native.c:1448 snd_pcm_action_single sound/core/pcm_native.c:1224 [inline] snd_pcm_action+0x143/0x170 sound/core/pcm_native.c:1305 snd_pcm_stop sound/core/pcm_native.c:1471 [inline] snd_pcm_drop+0x1ab/0x320 sound/core/pcm_native.c:2150 snd_pcm_kernel_ioctl+0x12f/0x240 sound/core/pcm_native.c:3362 snd_pcm_oss_sync+0x230/0x800 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x276/0x300 sound/core/oss/pcm_oss.c:2571 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.12+0x0/0x40 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (&new->fa_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 pipe_release+0x1ba/0x320 fs/pipe.c:729 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 pipe_release+0x1ba/0x320 fs/pipe.c:729 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:311 fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:890 fasync_helper+0x9e/0xb0 fs/fcntl.c:993 sock_fasync+0x94/0x140 net/socket.c:1325 __fput+0x712/0x920 fs/file_table.c:277 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 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:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 pipe_release+0x1ba/0x320 fs/pipe.c:729 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 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+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.0+0x0/0x40 ... acquired at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387 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:697 [inline] snd_timer_start sound/core/timer.c:690 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985 __snd_timer_user_ioctl.isra.0+0xda8/0x24c0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 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: 0 PID: 26626 Comm: syz-executor.4 Not tainted 5.14.0-rc6-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+0xcd/0x134 lib/dump_stack.c:105 print_bad_irq_dependency kernel/locking/lockdep.c:2565 [inline] check_irq_usage.cold+0x4c1/0x6b0 kernel/locking/lockdep.c:2804 check_prev_add kernel/locking/lockdep.c:3055 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a1f/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387 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:697 [inline] snd_timer_start sound/core/timer.c:690 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985 __snd_timer_user_ioctl.isra.0+0xda8/0x24c0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 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: 0033:0x4665e9 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:00007fbe5efcb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000000000000 RSI: 00000000000054a0 RDI: 0000000000000003 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffd2f2c4d0f R14: 00007fbe5efcb300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W