INFO: task syz-executor.0:2120 blocked for more than 140 seconds.
Not tainted 4.9.170+ #47
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D25064 2120 1 0x00000004
ffff8801d232df00 ffff8801d38a4200 ffff8801db621000 ffff8801d3040000
ffff8801db621018 ffff8801a795f988 ffffffff8280185e 0000000000000000
ffffffff830c1d40 00ff8801a795f9b0 ffff8801db6218f0 1ffff10034f2bf20
Call Trace:
[<00000000ca79c851>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
[<000000001a4bd0d7>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
[<000000001666642e>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
[<000000001666642e>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
[<000000002819e5aa>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
[<00000000e55ac713>] loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:638
[<000000005cec647c>] loop_clr_fd+0x7dd/0xa60 drivers/block/loop.c:1082
[<00000000a0a6e03f>] lo_ioctl+0x7b6/0x1a10 drivers/block/loop.c:1415
[<00000000cbe7a293>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
[<00000000cbe7a293>] blkdev_ioctl+0xe14/0x19e0 block/ioctl.c:590
[<0000000089625959>] block_ioctl+0xde/0x120 fs/block_dev.c:1696
[<000000005d36837c>] vfs_ioctl fs/ioctl.c:43 [inline]
[<000000005d36837c>] file_ioctl fs/ioctl.c:493 [inline]
[<000000005d36837c>] do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677
[<0000000081e0383a>] SYSC_ioctl fs/ioctl.c:694 [inline]
[<0000000081e0383a>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
[<000000008a225a4c>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285
[<00000000cc653b62>] 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: [<000000009da9a720>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
#0: (rcu_read_lock){......}, at: [<000000009da9a720>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
#1: (tasklist_lock){.+.+..}, at: [<00000000a6b541dd>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339
2 locks held by getty/2029:
#0: (&tty->ldisc_sem){++++++}, at: [<0000000060f4f27c>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+.+.}, at: [<00000000931ae63a>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.0/2120:
#0: (loop_ctl_mutex/1){+.+.+.}, at: [<00000000412f98cf>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405
#1: (&bdev->bd_mutex){+.+.+.}, at: [<000000002819e5aa>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
2 locks held by syz-executor.1/2123:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000c9bfeccc>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000009f2f1a5e>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622
1 lock held by syz-executor.5/16696:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000009c4795d9>] blkdev_put+0x2b/0x560 fs/block_dev.c:1629
2 locks held by syz-executor.5/16707:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000002ca8b1a8>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587
#1: (loop_index_mutex){+.+.+.}, at: [<000000003cb531c9>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664
3 locks held by syz-executor.3/16703:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<000000002ca8b1a8>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587
#1: (loop_index_mutex){+.+.+.}, at: [<000000003cb531c9>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664
#2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000e81dfed3>] __lo_release drivers/block/loop.c:1642 [inline]
#2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000e81dfed3>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665
2 locks held by syz-executor.4/16739:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000c9bfeccc>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000009f2f1a5e>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622
2 locks held by blkid/16737:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000c9bfeccc>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<000000009f2f1a5e>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622
1 lock held by blkid/16738:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000c9bfeccc>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
1 lock held by blkid/16740:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000c9bfeccc>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.170+ #47
ffff8801d98d7cc8 ffffffff81b4fb21 0000000000000000 0000000000000000
0000000000000000 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00
ffffffff81b5adbc 0000000000000000 0000000000000000 0000000000000000
Call Trace:
[<00000000e8e462be>] __dump_stack lib/dump_stack.c:15 [inline]
[<00000000e8e462be>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
[<00000000697c376a>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
[<00000000405caefc>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
[<000000003ed9768f>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
[<0000000037c8e1e9>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
[<0000000037c8e1e9>] check_hung_task kernel/hung_task.c:126 [inline]
[<0000000037c8e1e9>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
[<0000000037c8e1e9>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
[<00000000f9069da6>] kthread+0x278/0x310 kernel/kthread.c:211
[<00000000a3949c05>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff828108d2