INFO: task syz-executor.1:1854 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25640 1854 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x78/0x190 drivers/block/loop.c:1668 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.3:1855 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25592 1855 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.0:20750 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25640 20750 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.5:6308 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28344 6308 2747 0x80000002 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:874 INFO: task syz-executor.5:6337 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28920 6337 2747 0x80000002 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_release+0x19/0x190 drivers/block/loop.c:1667 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x903/0x2960 kernel/exit.c:874 INFO: task syz-executor.0:23285 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27552 23285 20750 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 iterate_bdevs+0xc2/0x25c fs/block_dev.c:2166 sys_sync+0xb8/0x150 fs/sync.c:116 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.5:1265 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29248 1265 2747 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:615 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1184 INFO: task syz-executor.5:1286 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29120 1286 2747 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:1268 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28880 1268 8771 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000b250f2fa>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1759: #0: (&tty->ldisc_sem){++++}, at: [<000000009a83b3ba>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000009e237133>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.1/1854: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002344b4b1>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<00000000b164a722>] lo_release+0x19/0x190 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [<0000000008b62372>] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [<0000000008b62372>] lo_release+0x78/0x190 drivers/block/loop.c:1668 2 locks held by syz-executor.3/1855: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d978834d>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000347d38ae>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.0/20750: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d978834d>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000347d38ae>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 1 lock held by syz-executor.5/6308: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000a8ee8a14>] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 2 locks held by syz-executor.5/6337: #0: (&bdev->bd_mutex){+.+.}, at: [<000000002344b4b1>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<00000000b164a722>] lo_release+0x19/0x190 drivers/block/loop.c:1667 1 lock held by syz-executor.0/23285: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000939c03b8>] iterate_bdevs+0xc2/0x25c fs/block_dev.c:2166 2 locks held by syz-executor.5/1265: #0: (loop_ctl_mutex/1){+.+.}, at: [<00000000d4a163b3>] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000c1e0acc5>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.5/1286: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d978834d>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by blkid/1268: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d978834d>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000347d38ae>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.113+ #61 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28452 Comm: syz-executor.4 Not tainted 4.14.113+ #61 task: 0000000036baf74f task.stack: 00000000221332be RIP: 0010:rol32 include/linux/bitops.h:102 [inline] RIP: 0010:jhash2 include/linux/jhash.h:138 [inline] RIP: 0010:hash_stack lib/stackdepot.c:161 [inline] RIP: 0010:depot_save_stack+0x246/0x418 lib/stackdepot.c:217 RSP: 0000:ffff8881c6547950 EFLAGS: 00000812 RAX: 0000000048e4a558 RBX: 00000000b64231fd RCX: 0000000000000003 RDX: 000000006225304a RSI: 0000000012982531 RDI: 00000000c47bac26 RBP: ffff8881c65479a8 R08: 0000000000000001 R09: 0000000000000001 R10: ffff88818a23b758 R11: 0000000000000001 R12: ffff888186906d20 R13: 0000000000000009 R14: ffff8881c65479c0 R15: ffff8881da97ee00 FS: 00007f564e9e2700(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005b7468c01c65 CR3: 000000019b7d2002 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: Code: b6 fe ff ff 4c 89 f2 89 f0 89 f3 03 42 04 03 32 89 c2 31 c3 c1 c2 0e 29 d3 89 da 31 de c1 c2 0b 29 d6 89 f2 31 f0 c1 ca 07 29 d0 <89> c2 31 c3 c1 c2 10 29 d3 89 da 31 de c1 c2 04 29 d6 31 f0 c1