INFO: task syz-executor.4:7877 blocked for more than 143 seconds. Not tainted 5.1.0-rc7+ #99 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D24608 7877 7876 0x00000000 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 blk_mq_freeze_queue_wait+0x138/0x2a0 block/blk-mq.c:159 blk_freeze_queue block/blk-mq.c:186 [inline] blk_mq_freeze_queue+0x1e/0x30 block/blk-mq.c:195 __loop_clr_fd+0x13c/0xd60 drivers/block/loop.c:1059 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+0x6f2/0x1d10 block/ioctl.c:605 block_ioctl+0xee/0x130 fs/block_dev.c:1934 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: 0033:0x458c17 Code: Bad RIP value. RSP: 002b:00007ffc9125aa48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c17 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 0000000000002cd2 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc9125aa80 R14: 00000000002357d2 R15: 00007ffc9125aa90 INFO: task syz-executor.1:16330 blocked for more than 144 seconds. Not tainted 5.1.0-rc7+ #99 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28384 16330 7868 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 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 __wait_rcu_gp+0x22a/0x2f0 kernel/rcu/update.c:349 synchronize_rcu.part.0+0xcf/0xe0 kernel/rcu/tree.c:3045 synchronize_rcu+0x27/0xa0 kernel/rcu/tree.c:3046 tracepoint_synchronize_unregister include/linux/tracepoint.h:85 [inline] perf_trace_event_unreg.isra.0+0xd0/0x220 kernel/trace/trace_event_perf.c:163 perf_uprobe_destroy+0xc3/0x130 kernel/trace/trace_event_perf.c:340 _free_event+0x356/0x13b0 kernel/events/core.c:4454 put_event+0x47/0x60 kernel/events/core.c:4540 perf_event_release_kernel+0x693/0xbe0 kernel/events/core.c:4646 perf_release+0x37/0x50 kernel/events/core.c:4656 __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: 0033:0x412b61 Code: f1 41 00 be 06 00 00 00 4c 89 f7 31 c0 e8 e7 0a 00 00 48 8b 7c 24 18 e8 bd 26 00 00 80 bb 9c 00 00 00 00 48 89 df 74 15 e8 bc <35> ff ff 31 db 48 c7 44 24 18 00 00 00 00 e9 eb 00 00 00 e8 a7 35 RSP: 002b:00007ffe02a58ec0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000412b61 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: 000000007573aa14 R09: 000000007573aa18 R10: 00007ffe02a58fa0 R11: 0000000000000293 R12: 000000000073c900 R13: 000000000073c900 R14: 0000000000235a41 R15: 000000000073bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 0000000062979bdb (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5057 1 lock held by rsyslogd/7740: #0: 00000000dbde0f43 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7830: #0: 0000000069d66557 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000092d2cf5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7831: #0: 000000007051f506 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c1a31c4f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7832: #0: 00000000a2aea4c8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d9b95003 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7833: #0: 00000000c65363a2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000159b9e65 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7834: #0: 000000003ca72f7f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000902acff5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7835: #0: 000000004eed2dbe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a44c4cf8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7836: #0: 00000000abef3260 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000093f46ceb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.2/7870: #0: 00000000be5e2c0a (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x19b/0x1660 fs/block_dev.c:1514 #1: 0000000076ceed8f (loop_ctl_mutex){+.+.}, at: lo_open+0x1d/0xd0 drivers/block/loop.c:1736 1 lock held by syz-executor.4/7877: #0: 0000000076ceed8f (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xd60 drivers/block/loop.c:1046 2 locks held by syz-executor.5/7881: #0: 00000000bd354ba4 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x19b/0x1660 fs/block_dev.c:1514 #1: 0000000076ceed8f (loop_ctl_mutex){+.+.}, at: lo_open+0x1d/0xd0 drivers/block/loop.c:1736 2 locks held by kworker/1:1/21786: #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: 0000000099a9816f ((wq_completion)events){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 00000000b2ee5f2c ((work_completion)(&ns->proc_work)){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 1 lock held by syz-executor.3/23906: 1 lock held by syz-executor.1/16330: #0: 000000002d5970ba (event_mutex){+.+.}, at: perf_uprobe_destroy+0x28/0x130 kernel/trace/trace_event_perf.c:338 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc7+ #99 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: