truncated loop4: p4 start 1854537728 is beyond EOD, truncated INFO: task syz-executor.3:2128 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.3 D25528 2128 1 0x00000004 ffff8801d63e17c0 0000000000000000 ffff8801db621000 ffff8801da6017c0 ffff8801db621018 ffff8801af227a28 ffffffff82801dde ffffffff82e2bc18 ffffffff812080d0 009bc34e2ce3b8b2 ffff8801db6218f0 1ffff10035e44f34 Call Trace: [<00000000051d2f39>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000ad0cc054>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<000000000aa617b0>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<000000000aa617b0>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 [<00000000d3639e90>] __blkdev_driver_ioctl block/ioctl.c:294 [inline] [<00000000d3639e90>] blkdev_ioctl+0xe14/0x19e0 block/ioctl.c:590 [<00000000c35d24f6>] block_ioctl+0xde/0x120 fs/block_dev.c:1696 [<00000000e23de094>] vfs_ioctl fs/ioctl.c:43 [inline] [<00000000e23de094>] file_ioctl fs/ioctl.c:493 [inline] [<00000000e23de094>] do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677 [<0000000074e952f4>] SYSC_ioctl fs/ioctl.c:694 [inline] [<0000000074e952f4>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [<000000000aefe140>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285 [<000000008d2256c0>] 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: [<00000000ee866d46>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<00000000ee866d46>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<00000000ee7c68f4>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 2 locks held by getty/2039: #0: (&tty->ldisc_sem){++++++}, at: [<00000000fc5ce77b>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<00000000d49a0d13>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.3/2128: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 3 locks held by syz-executor.0/2145: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000045c30d9d>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<000000002453ded5>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000f2f65776>] __lo_release drivers/block/loop.c:1642 [inline] #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000f2f65776>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 2 locks held by syz-executor.2/2149: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000000b7ed061>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by syz-executor.4/32502: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 1 lock held by blkid/32499: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 1 lock held by syz-executor.1/32507: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 2 locks held by syz-executor.5/32509: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006906624b>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.+.}, at: [<0000000065b70a1e>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by syz-executor.5/32515: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by blkid/32508: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000000b7ed061>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by blkid/32510: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 1 lock held by blkid/32513: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by blkid/32514: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000000c12123b>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000000b7ed061>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 ============================================= 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: [<00000000c9d004c3>] __dump_stack lib/dump_stack.c:15 [inline] [<00000000c9d004c3>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000b734f699>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000d61b9fa5>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000b9f97e8a>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000ddb41d40>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000ddb41d40>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000ddb41d40>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000ddb41d40>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<000000006b84ce07>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000b5f2e0a3>] 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