syzbot

WARNING: CPU: 1 PID: 4495 at kernel/events/core.c:331 event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4495 Comm: syz-executor633 Not tainted 4.17.0-rc2+ #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331
RSP: 0018:ffff8801daf07cf8 EFLAGS: 00010006
RAX: ffff8801ad02c200 RBX: ffff8801ae5bf800 RCX: ffffffff818fe36a
RDX: 0000000000010000 RSI: ffffffff818fe560 RDI: 0000000000000005
RBP: ffff8801daf07d98 R08: ffff8801ad02c200 R09: ffffed0035cb7f01
R10: ffffed0035cb7f01 R11: ffff8801ae5bf80b R12: 1ffff1003b5e0fa2
R13: ffff8801daf31400 R14: ffff8801d952e300 R15: ffff8801b6a04300
 perf_event_disable_local kernel/events/core.c:2180 [inline]
 perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809
 irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155
 irq_work_run+0x1d/0x50 kernel/irq_work.c:170
 smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21
 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
RSP: 0018:ffff8801adbcf708 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff09
RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 0000000000000000
RDX: 1ffffffff11a315d RSI: 0000000000000001 RDI: 0000000000000286
RBP: ffff8801adbcf718 R08: ffffed003b2a5d50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d952ea78
R13: ffff8801d952e300 R14: 0000000000000001 R15: 1ffff10035b79f15
 try_to_wake_up+0x102/0x1190 kernel/sched/core.c:2057
 wake_up_process kernel/sched/core.c:2126 [inline]
 wake_up_q+0xa4/0x100 kernel/sched/core.c:443
 __mutex_unlock_slowpath+0x422/0x8a0 kernel/locking/mutex.c:1070
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614
 __pipe_unlock fs/pipe.c:88 [inline]
 pipe_write+0xc64/0xeb0 fs/pipe.c:475
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x64d/0x960 fs/read_write.c:487
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0xf9/0x250 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4401e9
RSP: 002b:00007ffc40f4d9e8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000100000001 RCX: 00000000004401e9
RDX: 0000000000000012 RSI: 00000000004a1764 RDI: 0000000000000001
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000217 R12: 0000000000401710
R13: 00000000004017a0 R14: 0000000000000000 R15: 0000000000000000

======================================================
WARNING: possible circular locking dependency detected
4.17.0-rc2+ #22 Not tainted
------------------------------------------------------
syz-executor633/4495 is trying to acquire lock:
        (ptrval) ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
        (ptrval) (&ctx->lock){-.-.}, at: perf_ctx_lock kernel/events/core.c:157 [inline]
        (ptrval) (&ctx->lock){-.-.}, at: event_function_local.constprop.113+0x2a3/0x5c0 kernel/events/core.c:318

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ctx->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       perf_event_context_sched_out kernel/events/core.c:3129 [inline]
       __perf_event_task_sched_out+0x12df/0x1a30 kernel/events/core.c:3221
       perf_event_task_sched_out include/linux/perf_event.h:1103 [inline]
       prepare_task_switch kernel/sched/core.c:2636 [inline]
       context_switch kernel/sched/core.c:2813 [inline]
       __schedule+0xfed/0x1e30 kernel/sched/core.c:3490
       schedule+0xef/0x430 kernel/sched/core.c:3549
       exit_to_usermode_loop+0x220/0x310 arch/x86/entry/common.c:152
       prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
       syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
       do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #2 (&rq->lock){-.-.}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144
       rq_lock kernel/sched/sched.h:1799 [inline]
       task_fork_fair+0x8a/0x660 kernel/sched/fair.c:9967
       sched_fork+0x43e/0xb30 kernel/sched/core.c:2379
       copy_process.part.38+0x1c13/0x6e90 kernel/fork.c:1764
       copy_process kernel/fork.c:1607 [inline]
       _do_fork+0x291/0x12a0 kernel/fork.c:2088
       kernel_thread+0x34/0x40 kernel/fork.c:2147
       rest_init+0x22/0xe4 init/main.c:407
       start_kernel+0x906/0x92d init/main.c:737
       x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:445
       x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:426
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963
       wake_up_process+0x10/0x20 kernel/sched/core.c:2126
       __up.isra.1+0x1b8/0x290 kernel/locking/semaphore.c:262
       up+0x12f/0x1b0 kernel/locking/semaphore.c:187
       __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:242
       console_unlock+0x7d6/0x1100 kernel/printk/printk.c:2417
       do_con_write+0x12b2/0x2280 drivers/tty/vt/vt.c:2437
       con_write+0x25/0xc0 drivers/tty/vt/vt.c:2786
       process_output_block drivers/tty/n_tty.c:579 [inline]
       n_tty_write+0x6b9/0x1180 drivers/tty/n_tty.c:2308
       do_tty_write drivers/tty/tty_io.c:958 [inline]
       tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042
       __vfs_write+0x10b/0x960 fs/read_write.c:485
       vfs_write+0x1f8/0x560 fs/read_write.c:549
       ksys_write+0xf9/0x250 fs/read_write.c:598
       __do_sys_write fs/read_write.c:610 [inline]
       __se_sys_write fs/read_write.c:607 [inline]
       __x64_sys_write+0x73/0xb0 fs/read_write.c:607
       do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 ((console_sem).lock){-...}:
       lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2229
       console_trylock_spinning kernel/printk/printk.c:1643 [inline]
       vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
       vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
       printk+0x9e/0xba kernel/printk/printk.c:1980
       __warn.cold.8+0x73/0x1b3 kernel/panic.c:518
       report_bug+0x252/0x2d0 lib/bug.c:186
       fixup_bug arch/x86/kernel/traps.c:178 [inline]
       do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
       do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
       invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
       event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331
       perf_event_disable_local kernel/events/core.c:2180 [inline]
       perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809
       irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155
       irq_work_run+0x1d/0x50 kernel/irq_work.c:170
       smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21
       irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
       arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
       _raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
       try_to_wake_up+0x102/0x1190 kernel/sched/core.c:2057
       wake_up_process kernel/sched/core.c:2126 [inline]
       wake_up_q+0xa4/0x100 kernel/sched/core.c:443
       __mutex_unlock_slowpath+0x422/0x8a0 kernel/locking/mutex.c:1070
       mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614
       __pipe_unlock fs/pipe.c:88 [inline]
       pipe_write+0xc64/0xeb0 fs/pipe.c:475
       call_write_iter include/linux/fs.h:1784 [inline]
       new_sync_write fs/read_write.c:474 [inline]
       __vfs_write+0x64d/0x960 fs/read_write.c:487
       vfs_write+0x1f8/0x560 fs/read_write.c:549
       ksys_write+0xf9/0x250 fs/read_write.c:598
       __do_sys_write fs/read_write.c:610 [inline]
       __se_sys_write fs/read_write.c:607 [inline]
       __x64_sys_write+0x73/0xb0 fs/read_write.c:607
       do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  (console_sem).lock --> &rq->lock --> &ctx->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ctx->lock);
                               lock(&rq->lock);
                               lock(&ctx->lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

2 locks held by syz-executor633/4495:
 #0:         (ptrval) (&cpuctx_lock){-.-.}, at: perf_ctx_lock kernel/events/core.c:155 [inline]
 #0:         (ptrval) (&cpuctx_lock){-.-.}, at: event_function_local.constprop.113+0x282/0x5c0 kernel/events/core.c:318
 #1:         (ptrval) (&ctx->lock){-.-.}, at: perf_ctx_lock kernel/events/core.c:157 [inline]
 #1:         (ptrval) (&ctx->lock){-.-.}, at: event_function_local.constprop.113+0x2a3/0x5c0 kernel/events/core.c:318

stack backtrace:
CPU: 1 PID: 4495 Comm: syz-executor633 Not tainted 4.17.0-rc2+ #22
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_circular_bug.isra.36.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1223
 check_prev_add kernel/locking/lockdep.c:1863 [inline]
 check_prevs_add kernel/locking/lockdep.c:1976 [inline]
 validate_chain kernel/locking/lockdep.c:2417 [inline]
 __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3431
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2229
 console_trylock_spinning kernel/printk/printk.c:1643 [inline]
 vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
 printk+0x9e/0xba kernel/printk/printk.c:1980
 __warn.cold.8+0x73/0x1b3 kernel/panic.c:518
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331
RSP: 0018:ffff8801daf07cf8 EFLAGS: 00010006
RAX: ffff8801ad02c200 RBX: ffff8801ae5bf800 RCX: ffffffff818fe36a
RDX: 0000000000010000 RSI: ffffffff818fe560 RDI: 0000000000000005
RBP: ffff8801daf07d98 R08: ffff8801ad02c200 R09: ffffed0035cb7f01
R10: ffffed0035cb7f01 R11: ffff8801ae5bf80b R12: 1ffff1003b5e0fa2
R13: ffff8801daf31400 R14: ffff8801d952e300 R15: ffff8801b6a04300
 perf_event_disable_local kernel/events/core.c:2180 [inline]
 perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809
 irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155
 irq_work_run+0x1d/0x50 kernel/irq_work.c:170
 smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21
 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184
RSP: 0018:ffff8801adbcf708 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff09
RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 0000000000000000
RDX: 1ffffffff11a315d RSI: 0000000000000001 RDI: 0000000000000286
RBP: ffff8801adbcf718 R08: ffffed003b2a5d50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d952ea78
R13: ffff8801d952e300 R14: 0000000000000001 R15: 1ffff10035b79f15
 try_to_wake_up+0x102/0x1190 kernel/sched/core.c:2057
 wake_up_process kernel/sched/core.c:2126 [inline]
 wake_up_q+0xa4/0x100 kernel/sched/core.c:443
 __mutex_unlock_slowpath+0x422/0x8a0 kernel/locking/mutex.c:1070
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614
 __pipe_unlock fs/pipe.c:88 [inline]
 pipe_write+0xc64/0xeb0 fs/pipe.c:475
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x64d/0x960 fs/read_write.c:487
Lost 22 message(s)!
Shutting down cpus with NMI
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..