INFO: task syz-executor.4:1867 blocked for more than 140 seconds. Not tainted 4.14.114+ #63 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25480 1867 1846 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x78/0x190 drivers/block/loop.c:1668 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.3:15707 blocked for more than 140 seconds. Not tainted 4.14.114+ #63 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D26672 15707 1857 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:615 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1184 INFO: task blkid:15738 blocked for more than 140 seconds. Not tainted 4.14.114+ #63 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27800 15738 3133 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000267c11ff>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541 2 locks held by getty/1759: #0: (&tty->ldisc_sem){++++}, at: [<000000000d90ab0d>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ce520d8b>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.4/1867: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000a0ce7a73>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<00000000497fb8b9>] lo_release+0x19/0x190 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [<000000004c495328>] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [<000000004c495328>] lo_release+0x78/0x190 drivers/block/loop.c:1668 2 locks held by syz-executor.3/15707: #0: (loop_ctl_mutex/1){+.+.}, at: [<000000007ed843c7>] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [<000000006d4b6a9f>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by blkid/15738: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000afc842bd>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000000ab674cb>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.114+ #63 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7892 Comm: syz-executor.2 Not tainted 4.14.114+ #63 task: 00000000ae95605e task.stack: 00000000586021b9 RIP: 0010:arch_local_irq_disable arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:796 [inline] RIP: 0010:lock_is_held_type+0x5e/0x150 kernel/locking/lockdep.c:4025 RSP: 0018:ffff8881ca197d58 EFLAGS: 00000046 RAX: 0000000000000246 RBX: 0000000000000246 RCX: 1ffffffff79825bc RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8881a1b7882c RBP: ffff8881d678add8 R08: 00000000000017d0 R09: 0000000000040094 R10: ffff8881a1b78830 R11: 0000000000000001 R12: ffff8881d1419cc0 R13: 0000000000000021 R14: ffff8881d678ad04 R15: 0000000000000000 FS: 00007fa0c0e40700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1aefa861f3 CR3: 00000001d728a005 CR4: 00000000001606a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_is_held include/linux/lockdep.h:437 [inline] expand_files+0x3ec/0x690 fs/file.c:206 SYSC_dup3 fs/file.c:893 [inline] SyS_dup3+0xf2/0x360 fs/file.c:877 SYSC_dup2 fs/file.c:923 [inline] SyS_dup2+0x25/0x300 fs/file.c:911 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Code: 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d9 00 00 00 8b 83 2c 08 00 00 85 c0 0f 85 b9 00 00 00 9c 58 0f 1f 44 00 00 48 89 c3 fa <66> 0f 1f 44 00 00 65 4c 8b 24 25 c0 de 01 00 49 8d bc 24 2c 08