INFO: task syz-executor0:2093 blocked for more than 140 seconds. Not tainted 4.9.130+ #48 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D26520 2093 2076 0x00000000 ffff8801d1658000 0000000000000000 ffff8801cf708580 ffffffff83029180 ffff8801db621018 ffff8801b7bd7330 ffffffff827f2d92 0000000000000000 ffffffff83c74b00 ffff8801d16588a8 00000000000043a2 ffff8801db6218f0 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] schedule_timeout+0x735/0xe20 kernel/time/timer.c:1771 [] do_wait_for_common kernel/sched/completion.c:75 [inline] [] __wait_for_common kernel/sched/completion.c:93 [inline] [] wait_for_common+0x3ef/0x5d0 kernel/sched/completion.c:101 [] wait_for_completion+0x18/0x20 kernel/sched/completion.c:122 [] kthread_stop+0xa6/0x5d0 kernel/kthread.c:519 [] destroy_workqueue+0x3ee/0x620 kernel/workqueue.c:4069 [] bioset_free+0x56/0x360 block/bio.c:1868 [] blk_release_queue+0x1a4/0x290 block/blk-sysfs.c:653 [] kobject_cleanup lib/kobject.c:643 [inline] [] kobject_release lib/kobject.c:672 [inline] [] kref_sub include/linux/kref.h:73 [inline] [] kref_put include/linux/kref.h:98 [inline] [] kobject_put+0x148/0x250 lib/kobject.c:689 [] blk_put_queue+0x19/0x20 block/blk-core.c:384 [] disk_release+0x24c/0x330 block/genhd.c:1146 [] device_release+0x7e/0x220 drivers/base/core.c:247 [] kobject_cleanup lib/kobject.c:643 [inline] [] kobject_release lib/kobject.c:672 [inline] [] kref_sub include/linux/kref.h:73 [inline] [] kref_put include/linux/kref.h:98 [inline] [] kobject_put+0x148/0x250 lib/kobject.c:689 [] put_disk+0x23/0x30 block/genhd.c:1358 [] __blkdev_get+0x57d/0xd60 fs/block_dev.c:1374 [] blkdev_get+0x2da/0x920 fs/block_dev.c:1416 [] blkdev_open+0x1a5/0x250 fs/block_dev.c:1571 [] do_dentry_open+0x3ef/0xc90 fs/open.c:766 [] vfs_open+0x11c/0x210 fs/open.c:879 [] do_last fs/namei.c:3410 [inline] [] path_openat+0x542/0x2790 fs/namei.c:3534 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open+0x2d/0x40 fs/open.c:1085 [] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 2 locks held by getty/2033: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor0/2076: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor1/2077: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor5/2078: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor2/2079: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor3/2080: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor4/2081: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor4/7874: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor4/7881: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor4/7893: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor5/7875: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor5/7885: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor5/7890: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor5/7894: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor3/7889: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor1/7879: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor1/7887: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor2/7883: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor2/7886: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by syz-executor2/7892: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by bioset/7888: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 1 lock held by blkid/7896: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.130+ #48 ffff8801d9907d08 ffffffff81b36c99 0000000000000000 0000000000000001 0000000000000001 0000000000000001 ffffffff81098180 ffff8801d9907d40 ffffffff81b41da9 0000000000000001 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6ad/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff82801c26