INFO: task syz-executor.1:1869 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25312 1869 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143f0 RSP: 002b:00007ffca06b1648 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000272e48 RCX: 00000000004143f0 RDX: 00007ffca06b16da RSI: 0000000000000002 RDI: 00007ffca06b16d0 RBP: 000000000000217a R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca06b1680 R14: 0000000000272d1d R15: 00007ffca06b1690 INFO: task syz-executor.3:18726 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25312 18726 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143f0 RSP: 002b:00007ffd6d61fa48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000272e2f RCX: 00000000004143f0 RDX: 00007ffd6d61fada RSI: 0000000000000002 RDI: 00007ffd6d61fad0 RBP: 00000000000000b9 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6d61fa80 R14: 0000000000272db5 R15: 00007ffd6d61fa90 INFO: task syz-executor.5:20349 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25312 20349 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143f0 RSP: 002b:00007ffd787e6588 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000273086 RCX: 00000000004143f0 RDX: 00007ffd787e661a RSI: 0000000000000002 RDI: 00007ffd787e6610 RBP: 0000000000000068 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd787e65c0 R14: 0000000000272d57 R15: 00007ffd787e65d0 INFO: task syz-executor.2:21645 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25312 21645 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143f0 RSP: 002b:00007ffc76254e08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000002730b4 RCX: 00000000004143f0 RDX: 00007ffc76254e9a RSI: 0000000000000002 RDI: 00007ffc76254e90 RBP: 000000000000000f R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc76254e40 R14: 0000000000272d87 R15: 00007ffc76254e50 INFO: task syz-executor.4:22245 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27120 22245 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2e9bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000019 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2e9c6d4 R13: 00000000004c420d R14: 00000000004d9848 R15: 00000000ffffffff INFO: task syz-executor.4:22260 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29904 22260 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2e7ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 000000000000001a RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2e7b6d4 R13: 00000000004c420d R14: 00000000004d9848 R15: 00000000ffffffff INFO: task syz-executor.4:22272 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28928 22272 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2e59c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 000000000000001a RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2e5a6d4 R13: 00000000004c41e2 R14: 00000000004d9818 R15: 00000000ffffffff INFO: task syz-executor.4:22276 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29616 22276 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2e38c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 000000000000001b RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2e396d4 R13: 00000000004c41e2 R14: 00000000004d9818 R15: 00000000ffffffff INFO: task syz-executor.4:22278 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28592 22278 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2e17c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 000000000000001a RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2e186d4 R13: 00000000004c41e2 R14: 00000000004d9818 R15: 00000000ffffffff INFO: task syz-executor.4:22281 blocked for more than 140 seconds. Not tainted 4.14.157-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D30304 22281 21973 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a679 RSP: 002b:00007f6aa2dd5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 000000000000001b RBP: 000000000075c310 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6aa2dd66d4 R13: 00000000004c41e2 R14: 00000000004d9818 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000dfd779c8>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1763: #0: (&tty->ldisc_sem){++++}, at: [<000000003d1a0c48>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000008b720053>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/1869: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000008148b7cd>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.3/18726: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000008148b7cd>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.5/20349: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000008148b7cd>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.2/21645: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000008148b7cd>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/22245: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<00000000e9bb5ea5>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 1 lock held by syz-executor.4/22260: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.4/22272: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.4/22276: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.4/22278: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.4/22281: #0: (loop_index_mutex){+.+.}, at: [<00000000ce45e125>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 2 locks held by syz-executor.0/22261: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000ba72e165>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<0000000097630313>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.0/22284: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by blkid/22267: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000bbee697b>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<000000008148b7cd>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.157-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe5/0x154 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x119/0x147 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x629/0xbe0 kernel/hung_task.c:274 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffffb60a7673