loop1: p1 start 1 is beyond EOD, truncated loop1: p2 start 101 is beyond EOD, truncated loop1: p3 start 201 is beyond EOD, truncated loop1: p4 start 301 is beyond EOD, truncated INFO: task syz-executor.3:2123 blocked for more than 140 seconds. Not tainted 4.9.170+ #48 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25400 2123 1 0x00000004 ffff8801d8dddf00 ffff8801a30f6880 ffff8801db721000 ffff8801a3c417c0 ffff8801db721018 ffff8801a8a4fb28 ffffffff82801a4e 0000000041b58ab3 ffff8801a8a4faa0 00ffffff81bb61ac ffff8801db7218f0 1ffff10035149f54 Call Trace: [<00000000fa1ab39f>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<0000000052ad5ee1>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<00000000bf057d49>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<00000000bf057d49>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<00000000fba422e4>] __lo_release drivers/block/loop.c:1642 [inline] [<00000000fba422e4>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 [<000000009401da69>] __blkdev_put+0x461/0x840 fs/block_dev.c:1606 [<00000000f5cef786>] blkdev_put+0x88/0x560 fs/block_dev.c:1671 [<000000007279c737>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1678 [<0000000023a0313d>] __fput+0x274/0x720 fs/file_table.c:208 [<00000000b3037e34>] ____fput+0x16/0x20 fs/file_table.c:244 [<00000000a60e4838>] task_work_run+0x108/0x180 kernel/task_work.c:116 [<00000000adbadafd>] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [<00000000adbadafd>] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:162 [<0000000000803889>] prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] [<0000000000803889>] syscall_return_slowpath arch/x86/entry/common.c:263 [inline] [<0000000000803889>] do_syscall_64+0x3f7/0x570 arch/x86/entry/common.c:290 [<00000000cb326c40>] 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: [<0000000022efb60d>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<0000000022efb60d>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<00000000fe1e92b9>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339 2 locks held by getty/2028: #0: (&tty->ldisc_sem){++++++}, at: [<0000000003f12b59>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<00000000b87b36b0>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.3/2123: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000003f9d0ad6>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<00000000db6999b9>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000fba422e4>] __lo_release drivers/block/loop.c:1642 [inline] #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000fba422e4>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 2 locks held by syz-executor.2/17130: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000d899ee23>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001ea77c88>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.0/29472: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000d899ee23>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001ea77c88>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.1/26711: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000006fd2a6de>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.+.}, at: [<000000003500c33b>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 2 locks held by blkid/26730: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000d899ee23>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000001ea77c88>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.170+ #48 ffff8801d98d7cc8 ffffffff81b4fb21 0000000000000000 0000000000000000 0000000000000000 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00 ffffffff81b5adbc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [<0000000054f06d54>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000054f06d54>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<000000003c54bec6>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<000000000e4bd3b1>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000a0eee7d1>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000518f936d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000518f936d>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000518f936d>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000518f936d>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<000000005e5fdbc7>] kthread+0x278/0x310 kernel/kthread.c:211 [<0000000018f51804>] 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 CPU: 1 PID: 6795 Comm: syz-executor.4 Not tainted 4.9.170+ #48 task: 00000000c9270a40 task.stack: 00000000e4bb1afc RIP: 0033:[<0000000000401584>] c [<00000000d0e2c757>] 0x401584 RSP: 002b:00007fed3f2d9690 EFLAGS: 00000206 RAX: 000000006a04b7b2 RBX: 000000000000000b RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 00007fed3f2d96c0 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fed3f2da700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000018dc308 CR3: 00000001a9214000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600