======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc6-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.1/8508 just changed the state of lock: ffff888147641148 (&timer->lock){..-.}-{2:2}, at: snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 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: 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 *** 1 lock held by syz-executor.1/8508: #0: ffffc90000dc0d70 ((&priv->tlist)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #0: ffffc90000dc0d70 ((&priv->tlist)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411 the shortest dependencies between 2nd lock and 1st 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 sock_wake_async+0xd2/0x160 net/socket.c:1354 sk_wake_async include/net/sock.h:2327 [inline] sk_wake_async include/net/sock.h:2323 [inline] sock_def_readable+0x349/0x4e0 net/core/sock.c:3017 unix_dgram_sendmsg+0x1032/0x1d30 net/unix/af_unix.c:1852 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 ____sys_sendmsg+0x331/0x810 net/socket.c:2392 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446 __sys_sendmmsg+0x195/0x470 net/socket.c:2532 __do_sys_sendmmsg net/socket.c:2561 [inline] __se_sys_sendmmsg net/socket.c:2558 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2558 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 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 sock_wake_async+0xd2/0x160 net/socket.c:1354 sk_wake_async include/net/sock.h:2327 [inline] sk_wake_async include/net/sock.h:2323 [inline] sock_def_readable+0x349/0x4e0 net/core/sock.c:3017 unix_dgram_sendmsg+0x1032/0x1d30 net/unix/af_unix.c:1852 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 ____sys_sendmsg+0x331/0x810 net/socket.c:2392 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446 __sys_sendmmsg+0x195/0x470 net/socket.c:2532 __do_sys_sendmmsg net/socket.c:2561 [inline] __se_sys_sendmmsg net/socket.c:2558 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2558 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_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 __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 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 } ... key at: [] __key.0+0x0/0x40 ... acquired at: __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 -> (&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 get_current arch/x86/include/asm/current.h:15 [inline] finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4555 context_switch kernel/sched/core.c:4684 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x24e/0x690 kernel/time/hrtimer.c:1896 hrtimer_nanosleep+0x1f9/0x4a0 kernel/time/hrtimer.c:1949 common_nsleep+0xa2/0xc0 kernel/time/posix-timers.c:1227 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1267 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] __x64_sys_clock_nanosleep+0x2f4/0x430 kernel/time/posix-timers.c:1245 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_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [inline] snd_timer_close_locked+0x63/0xbb0 sound/core/timer.c:396 snd_timer_close+0x87/0xf0 sound/core/timer.c:463 snd_seq_timer_close+0x8c/0xe0 sound/core/seq/seq_timer.c:326 queue_delete+0x4a/0xa0 sound/core/seq/seq_queue.c:134 snd_seq_queue_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:555 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:280 seq_free_client1 sound/core/seq/seq_clientmgr.c:273 [inline] seq_free_client+0x7b/0xf0 sound/core/seq/seq_clientmgr.c:301 snd_seq_release+0x4d/0xe0 sound/core/seq/seq_clientmgr.c:382 __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 ... acquired at: mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969 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 get_current arch/x86/include/asm/current.h:15 [inline] finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4555 context_switch kernel/sched/core.c:4684 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x24e/0x690 kernel/time/hrtimer.c:1896 hrtimer_nanosleep+0x1f9/0x4a0 kernel/time/hrtimer.c:1949 common_nsleep+0xa2/0xc0 kernel/time/posix-timers.c:1227 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1267 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] __x64_sys_clock_nanosleep+0x2f4/0x430 kernel/time/posix-timers.c:1245 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: 8508 Comm: syz-executor.1 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_irq_inversion_bug kernel/locking/lockdep.c:203 [inline] check_usage_forwards kernel/locking/lockdep.c:4031 [inline] mark_lock_irq kernel/locking/lockdep.c:4163 [inline] mark_lock.cold+0x86/0x8e kernel/locking/lockdep.c:4593 mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969 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 RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4555 Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 f3 3b dd 07 e8 fe e7 2b 00 fb 65 48 8b 1c 25 40 f0 01 00 <48> 8d bb 10 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900017efb40 EFLAGS: 00000202 RAX: 00000000002ac1d5 RBX: ffff888018343880 RCX: 1ffffffff1ad8a89 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900017efb80 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bd238 R11: 0000000000000001 R12: ffff8880b9d51b00 R13: ffff88801d9fd4c0 R14: ffff8880278ca300 R15: ffff8880b9d51b18 context_switch kernel/sched/core.c:4684 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x24e/0x690 kernel/time/hrtimer.c:1896 hrtimer_nanosleep+0x1f9/0x4a0 kernel/time/hrtimer.c:1949 common_nsleep+0xa2/0xc0 kernel/time/posix-timers.c:1227 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1267 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] __x64_sys_clock_nanosleep+0x2f4/0x430 kernel/time/posix-timers.c:1245 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: 0033:0x48a7b1 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:0000000000a9fd00 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000210 RCX: 000000000048a7b1 RDX: 0000000000a9fd40 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000a9fddc R08: 0000000000000000 R09: 00007fffd85ad080 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 000000000006616f R14: 0000000000000003 R15: 0000000000a9fe40 ---------------- Code disassembly (best guess): 0: 8b 3a mov (%rdx),%edi 2: 4c 89 e7 mov %r12,%rdi 5: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) c: ff d1 callq *%rcx e: 4d 85 ff test %r15,%r15 11: 75 bf jne 0xffffffd2 13: 4c 89 e7 mov %r12,%rdi 16: e8 f3 3b dd 07 callq 0x7dd3c0e 1b: e8 fe e7 2b 00 callq 0x2be81e 20: fb sti 21: 65 48 8b 1c 25 40 f0 mov %gs:0x1f040,%rbx 28: 01 00 * 2a: 48 8d bb 10 15 00 00 lea 0x1510(%rbx),%rdi <-- trapping instruction 31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 38: fc ff df 3b: 48 89 fa mov %rdi,%rdx 3e: 48 rex.W 3f: c1 .byte 0xc1