INFO: task syz-executor.4:3712 blocked for more than 143 seconds. Not tainted 5.0.0-next-20190306 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28232 3712 888 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_timeout+0x8ca/0xfd0 kernel/time/timer.c:1779 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:925 synchronize_srcu_expedited kernel/rcu/srcutree.c:950 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:1001 tracepoint_synchronize_unregister include/linux/tracepoint.h:84 [inline] perf_trace_event_unreg.isra.0+0xcb/0x220 kernel/trace/trace_event_perf.c:163 perf_trace_destroy+0xc1/0x100 kernel/trace/trace_event_perf.c:238 tp_perf_event_destroy+0x16/0x20 kernel/events/core.c:8574 _free_event+0x356/0x13b0 kernel/events/core.c:4452 put_event+0x47/0x60 kernel/events/core.c:4538 perf_event_release_kernel+0x693/0xc60 kernel/events/core.c:4644 perf_release+0x37/0x50 kernel/events/core.c:4654 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457f29 Code: Bad RIP value. RSP: 002b:00007fe9a2652c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000457f29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe9a26536d4 R13: 00000000004f4e52 R14: 00000000004ce9f8 R15: 00000000ffffffff INFO: task syz-executor.4:3735 blocked for more than 143 seconds. Not tainted 5.0.0-next-20190306 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D30120 3735 888 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 perf_trace_init+0x58/0x250 kernel/trace/trace_event_perf.c:218 perf_tp_event_init+0xa6/0x120 kernel/events/core.c:8590 perf_try_init_event+0x137/0x3f0 kernel/events/core.c:10009 perf_init_event kernel/events/core.c:10056 [inline] perf_event_alloc.part.0+0xfa0/0x3200 kernel/events/core.c:10326 perf_event_alloc kernel/events/core.c:10696 [inline] __do_sys_perf_event_open+0x830/0x24e0 kernel/events/core.c:10797 __se_sys_perf_event_open kernel/events/core.c:10686 [inline] __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10686 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457f29 Code: Bad RIP value. RSP: 002b:00007fe9a2631c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457f29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002025c000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fe9a26326d4 R13: 00000000004c4591 R14: 00000000004d7cf8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 0000000032a5dba0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5052 1 lock held by rsyslogd/7698: #0: 000000009725bca8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7810: #0: 00000000a011d131 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000008786143 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7811: #0: 000000004fffd61c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000050b8072f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7812: #0: 00000000aeea8977 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000efc50b6c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7813: #0: 00000000e58051d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003cf2636b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7814: #0: 000000006b0ea685 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a66fad51 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7815: #0: 00000000d32486a2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000882bb412 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7816: #0: 000000001fa36cd5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000db66b049 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 4 locks held by kworker/0:6/16350: 1 lock held by syz-executor.4/3712: #0: 00000000bab10526 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:236 3 locks held by syz-executor.4/3735: #0: 000000002c73455c (&sig->cred_guard_mutex){+.+.}, at: __do_sys_perf_event_open+0x6d2/0x24e0 kernel/events/core.c:10777 #1: 000000003142e6c9 (&pmus_srcu){....}, at: perf_event_alloc.part.0+0xd57/0x3200 kernel/events/core.c:10322 #2: 00000000bab10526 (event_mutex){+.+.}, at: perf_trace_init+0x58/0x250 kernel/trace/trace_event_perf.c:218 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.0.0-next-20190306 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: