INFO: task syz-executor.0:2105 blocked for more than 140 seconds.
Not tainted 4.9.184+ #5
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0 D25016 2105 1 0x00000004
0000000000000083 ffff8801d0d817c0 ffff8801d3b32100 ffff8801db621000
ffff8801d3a817c0 ffff8801db621018 ffff8801a7447988 ffffffff8280a5ce
ffff8801a74478f8 ffffffff81bbe70c 00ffffff81bbe70c ffff8801db6218f0
Call Trace:
[<00000000c15d3699>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
[<0000000098328ca3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
[<00000000ceff81de>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
[<00000000ceff81de>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
[<00000000cced676f>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
[<000000000ca51690>] loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:637
[<00000000c47ce5ec>] loop_clr_fd+0x7dd/0xa60 drivers/block/loop.c:1081
[<00000000c31b8298>] lo_ioctl+0x7e9/0x1b10 drivers/block/loop.c:1414
[<000000005e74bb63>] __blkdev_driver_ioctl block/ioctl.c:294 [inline]
[<000000005e74bb63>] blkdev_ioctl+0xe14/0x19e0 block/ioctl.c:590
[<0000000092e59700>] block_ioctl+0xde/0x120 fs/block_dev.c:1696
[<000000009593ff03>] vfs_ioctl fs/ioctl.c:43 [inline]
[<000000009593ff03>] file_ioctl fs/ioctl.c:493 [inline]
[<000000009593ff03>] do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677
[<00000000e062923b>] SYSC_ioctl fs/ioctl.c:694 [inline]
[<00000000e062923b>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
[<00000000be1bede6>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
[<00000000d8bc5748>] 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: [<000000005bef8e29>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
#0: (rcu_read_lock){......}, at: [<000000005bef8e29>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
#1: (tasklist_lock){.+.+..}, at: [<000000005589a102>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by rs:main Q:Reg/1884:
#0: (&f->f_pos_lock){+.+.+.}, at: [<00000000fafed031>] __fdget_pos+0xa8/0xd0 fs/file.c:782
#1: (sb_writers#4){.+.+.+}, at: [<0000000098c2d0ac>] file_start_write include/linux/fs.h:2646 [inline]
#1: (sb_writers#4){.+.+.+}, at: [<0000000098c2d0ac>] vfs_write+0x3e9/0x520 fs/read_write.c:558
1 lock held by rsyslogd/1886:
#0: (&f->f_pos_lock){+.+.+.}, at: [<00000000fafed031>] __fdget_pos+0xa8/0xd0 fs/file.c:782
2 locks held by getty/2014:
#0: (&tty->ldisc_sem){++++++}, at: [<000000002aa8b7da>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377
#1: (&ldata->atomic_read_lock){+.+...}, at: [<000000005122704b>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
2 locks held by syz-executor.0/2105:
#0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<00000000f333b8be>] lo_ioctl+0x8e/0x1b10 drivers/block/loop.c:1404
#1: (&bdev->bd_mutex){+.+.+.}, at: [<00000000cced676f>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189
2 locks held by syz-executor.2/4029:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<0000000032ef58ba>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
1 lock held by syz-executor.1/22870:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a32d31e1>] blkdev_put+0x2b/0x560 fs/block_dev.c:1629
2 locks held by syz-executor.1/22876:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (loop_index_mutex){+.+.+.}, at: [<0000000032ef58ba>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
1 lock held by syz-executor.1/22885:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
2 locks held by blkid/22872:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fa3e5e19>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587
#1: (loop_index_mutex){+.+.+.}, at: [<00000000bb529bb4>] lo_release+0x20/0x1b0 drivers/block/loop.c:1663
2 locks held by syz-executor.5/22877:
#0: (loop_index_mutex){+.+.+.}, at: [<00000000877de2bc>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973
#1: (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<00000000f10444f0>] loop_control_ioctl+0x17f/0x320 drivers/block/loop.c:1987
1 lock held by syz-executor.5/22888:
#0: (loop_index_mutex){+.+.+.}, at: [<00000000877de2bc>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973
1 lock held by syz-executor.5/22896:
#0: (loop_index_mutex){+.+.+.}, at: [<00000000877de2bc>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973
1 lock held by blkid/22880:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
3 locks held by blkid/22881:
#0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#1: (&bdev->bd_mutex/1){+.+...}, at: [<00000000b09c8515>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273
#2: (loop_index_mutex){+.+.+.}, at: [<0000000032ef58ba>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.184+ #5
ffff8801d98d7cc8 ffffffff81b580a1 0000000000000000 0000000000000000
0000000000000000 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00
ffffffff81b6333c 0000000000000000 0000000000000000 0000000000000000
Call Trace:
[<00000000fd37e137>] __dump_stack lib/dump_stack.c:15 [inline]
[<00000000fd37e137>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
[<0000000024880a27>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
[<00000000b6831e71>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
[<000000009805f09c>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
[<000000008682f369>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
[<000000008682f369>] check_hung_task kernel/hung_task.c:126 [inline]
[<000000008682f369>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
[<000000008682f369>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
[<00000000a5c02b22>] kthread+0x278/0x310 kernel/kthread.c:211
[<0000000071c1bb3d>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff82819721