INFO: task syz-executor.1:25554 blocked for more than 143 seconds. Not tainted 5.0.0+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28296 25554 8215 0x80000002 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:8575 _free_event+0x356/0x13b0 kernel/events/core.c:4453 put_event+0x47/0x60 kernel/events/core.c:4539 perf_event_release_kernel+0x693/0xc60 kernel/events/core.c:4645 perf_release+0x37/0x50 kernel/events/core.c:4655 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2575 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 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: 0033:0x458079 Code: Bad RIP value. RSP: 002b:00007ffed7252e38 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 000000000000002d RCX: 0000000000458079 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000073bf0c RBP: 000000000073bf00 R08: 000000000022c3fc R09: 000000000022c3fc R10: 00007ffed7252f00 R11: 0000000000000246 R12: 000000000022c43f R13: 000000000022c412 R14: 00000000000003e8 R15: 000000000073bf0c INFO: task syz-executor.2:25566 blocked for more than 144 seconds. Not tainted 5.0.0+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27872 25566 8217 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 __flush_work+0x4ab/0x8a0 kernel/workqueue.c:3039 flush_work+0x18/0x20 kernel/workqueue.c:3060 lru_add_drain_all+0x3a6/0x500 mm/swap.c:698 invalidate_bdev+0xa0/0xe0 fs/block_dev.c:97 __loop_clr_fd+0x387/0xd60 drivers/block/loop.c:1081 loop_clr_fd drivers/block/loop.c:1177 [inline] lo_ioctl+0x210/0x2150 drivers/block/loop.c:1546 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0xee8/0x1c40 block/ioctl.c:605 block_ioctl+0xee/0x130 fs/block_dev.c:1931 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ee7 Code: Bad RIP value. RSP: 002b:00007f6b0a3ffa88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6b0a3ffb30 RCX: 0000000000457ee7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000005 RBP: 00000000200002c0 R08: 00007f6b0a3ffb30 R09: 00007f6b0a3ffad0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 0000000000000000 R14: 00000000004dbe60 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1041: #0: 000000006ff4aad4 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 1 lock held by rsyslogd/8050: #0: 00000000407a71f5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8171: #0: 00000000086b953e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001380d71d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8172: #0: 000000003f56690d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000053f53fa1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8173: #0: 0000000068526807 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009841f3ab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8174: #0: 00000000949ae771 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001f6ed8d2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8175: #0: 00000000371872e2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000866523ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8176: #0: 00000000159ee585 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000039b506fd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8177: #0: 0000000067dca484 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000dd232804 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/8390: #0: 00000000a65ce803 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xbb/0x810 fs/block_dev.c:1831 #1: 00000000a97806f2 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:319 [inline] #1: 00000000a97806f2 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x56/0x90 lib/refcount.c:314 1 lock held by syz-executor.4/9195: #0: 00000000e0bf283b (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:317 [inline] #0: 00000000e0bf283b (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x26f/0x5b0 kernel/rcu/tree_exp.h:758 2 locks held by syz-executor.1/14644: #0: 00000000c8e8ea6b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 #1: 00000000e0bf283b (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:317 [inline] #1: 00000000e0bf283b (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x26f/0x5b0 kernel/rcu/tree_exp.h:758 3 locks held by kworker/0:2/12510: #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 0000000045e70cac ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000c9cad8a8 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 00000000c8e8ea6b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by syz-executor.3/9158: #0: 0000000004a4e7a5 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:236 1 lock held by syz-executor.0/9480: #0: 00000000c8e8ea6b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 3 locks held by kworker/1:5/3721: 1 lock held by syz-executor.1/25554: #0: 0000000004a4e7a5 (event_mutex){+.+.}, at: perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:236 2 locks held by syz-executor.2/25566: #0: 00000000092cc621 (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xd60 drivers/block/loop.c:1046 #1: 000000000da1e31d (lock#7){+.+.}, at: lru_add_drain_all+0x60/0x500 mm/swap.c:680 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.0.0+ #22 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 0 to CPUs 1: