FAT-fs (loop0): codepage cp437 not found INFO: task syz-executor.5:2104 blocked for more than 140 seconds. Not tainted 4.9.171+ #49 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24216 2104 1 0x00000004 ffff8801ce8f2f80 0000000000000000 ffff8801db721000 ffff8801ce67af80 ffff8801db721018 ffff8801b1dbfb28 ffffffff82801dde ffff8801ce8f2f80 ffff8801b1dbfc00 0000000000000046 ffff8801db7218f0 1ffff100363b7f54 Call Trace: [<00000000b7e28646>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000c4aebbc0>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<0000000020a115ff>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<0000000020a115ff>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<00000000972ece13>] __lo_release drivers/block/loop.c:1642 [inline] [<00000000972ece13>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 [<0000000025a01a09>] __blkdev_put+0x461/0x840 fs/block_dev.c:1606 [<00000000148f3c03>] blkdev_put+0x88/0x560 fs/block_dev.c:1671 [<000000004b97d6fc>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1678 [<0000000027a27c56>] __fput+0x274/0x720 fs/file_table.c:208 [<00000000f4afa9f9>] ____fput+0x16/0x20 fs/file_table.c:244 [<000000005e81906c>] task_work_run+0x108/0x180 kernel/task_work.c:116 [<00000000ff295b1d>] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [<00000000ff295b1d>] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:162 [<00000000b115c530>] prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] [<00000000b115c530>] syscall_return_slowpath arch/x86/entry/common.c:263 [inline] [<00000000b115c530>] do_syscall_64+0x3f7/0x570 arch/x86/entry/common.c:290 [<00000000ff1a644f>] 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: [<000000007f12d194>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<000000007f12d194>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<00000000011b2206>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 2 locks held by getty/2030: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.5/2104: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000318affc5>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<0000000080b349cd>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000972ece13>] __lo_release drivers/block/loop.c:1642 [inline] #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000972ece13>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 2 locks held by syz-executor.3/2114: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001f47752c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.4/2119: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001f47752c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by syz-executor.2/2124: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by syz-executor.3/19592: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/19830: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/19857: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/19999: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/20041: #0: (&tty->ldisc_sem){++++++}, at: [<0000000098706c14>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000096f7c0d4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/3070: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000cf23f13c>] blkdev_put+0x2b/0x560 fs/block_dev.c:1629 1 lock held by syz-executor.0/3071: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000cf23f13c>] blkdev_put+0x2b/0x560 fs/block_dev.c:1629 2 locks held by syz-executor.1/3073: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<00000000767b0882>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.+.}, at: [<0000000071ba679e>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by syz-executor.1/3084: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by blkid/3076: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001f47752c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by blkid/3080: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001f47752c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by blkid/3081: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001f47752c>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by blkid/3082: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000a2a958db>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.171+ #49 ffff8801d98d7cc8 ffffffff81b4fb61 0000000000000000 0000000000000000 0000000000000000 ffffffff81097501 dffffc0000000000 ffff8801d98d7d00 ffffffff81b5adfc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [<000000009bc866ce>] __dump_stack lib/dump_stack.c:15 [inline] [<000000009bc866ce>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<000000007087391d>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<000000001874f8d5>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000df085b2b>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000ad44aa32>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000ad44aa32>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000ad44aa32>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000ad44aa32>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<00000000d12d6bf5>] kthread+0x278/0x310 kernel/kthread.c:211 [<000000007034ca6e>] 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 0xffffffff82810e52