INFO: task syz-executor.0:7094 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D24992 7094 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_release+0x1e/0x1b0 drivers/block/loop.c:1667 __blkdev_put+0x436/0x7f0 fs/block_dev.c:1791 blkdev_put+0x88/0x510 fs/block_dev.c:1856 blkdev_close+0x8b/0xb0 fs/block_dev.c:1863 __fput+0x277/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x119/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 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+0x4a9/0x630 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412b40 RSP: 002b:00007ffd7842ead8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000412b40 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 0000000000000090 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7842eb10 R14: 000000000003cda1 R15: 00007ffd7842eb20 INFO: task syz-executor.5:7096 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24992 7096 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x2c9/0x1120 fs/block_dev.c:1472 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d20 RSP: 002b:00007ffe2eab1a18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000003ce2c RCX: 0000000000412d20 RDX: 00007ffe2eab1aaa RSI: 0000000000000002 RDI: 00007ffe2eab1aa0 RBP: 000000000000008c R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe2eab1a50 R14: 000000000003cda1 R15: 00007ffe2eab1a60 INFO: task syz-executor.4:7099 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25168 7099 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x2c9/0x1120 fs/block_dev.c:1472 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d20 RSP: 002b:00007ffdc09e1b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000003ce16 RCX: 0000000000412d20 RDX: 00007ffdc09e1b9a RSI: 0000000000000002 RDI: 00007ffdc09e1b90 RBP: 0000000000000077 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc09e1b40 R14: 000000000003cd9f R15: 00007ffdc09e1b50 INFO: task syz-executor.1:7738 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28592 7738 7098 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 iterate_bdevs+0xc4/0x263 fs/block_dev.c:2166 sys_sync+0xa8/0x130 fs/sync.c:116 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x200002d0 RSP: 002b:00007f1d022bbbd8 EFLAGS: 00000a83 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00000000200002d0 RDX: 3f3171cfeca47408 RSI: 0000000000000000 RDI: 00007f1d02445471 RBP: 00000000000000f0 R08: 0000000000000005 R09: 0000000000000006 R10: 0000000000000007 R11: 0000000000000a83 R12: 000000000000000b R13: 000000000000000c R14: 000000000000000d R15: 00000000ffffffff INFO: task syz-executor.1:7819 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29056 7819 7098 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 iterate_bdevs+0xc4/0x263 fs/block_dev.c:2166 sys_sync+0xa8/0x130 fs/sync.c:116 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x200002d0 RSP: 002b:00007f1d022bbbd8 EFLAGS: 00000a83 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00000000200002d0 RDX: 3f3171cfeca47408 RSI: 0000000000000000 RDI: 00007f1d0269e871 RBP: 00000000000000f0 R08: 0000000000000005 R09: 0000000000000006 R10: 0000000000000007 R11: 0000000000000a83 R12: 000000000000000b R13: 000000000000000c R14: 000000000000000d R15: 00000000ffffffff INFO: task syz-executor.2:8632 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D26736 8632 7100 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c17 RSP: 002b:00007f84a4c50a88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f84a4c50b40 RCX: 0000000000458c17 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000006 RBP: 0000000000000001 R08: 00007f84a4c50b40 R09: 00007f84a4c50ae0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00000000004c79d9 R14: 00000000004dda18 R15: 00000000ffffffff INFO: task syz-executor.2:8646 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27856 8646 7100 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d41 RSP: 002b:00007f84a4c0ea80 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000020000068 RCX: 0000000000412d41 RDX: 00007f84a4c0eb0a RSI: 0000000000000002 RDI: 00007f84a4c0eb00 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000004 R13: 00000000004c79d9 R14: 00000000004dda18 R15: 00000000ffffffff INFO: task syz-executor.1:8629 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27408 8629 7098 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:615 loop_set_status+0xc28/0x1200 drivers/block/loop.c:1184 loop_set_status64+0xa6/0xf0 drivers/block/loop.c:1302 lo_ioctl+0x5c1/0x1c70 drivers/block/loop.c:1432 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c17 RSP: 002b:00007f1d022bb9f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1d022bc6d4 RCX: 0000000000458c17 RDX: 00007f1d022bbab0 RSI: 0000000000004c04 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000004 R13: 0000000000000004 R14: 0000000000000005 R15: 00000000ffffffff INFO: task syz-executor.3:8630 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27744 8630 7101 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 __blkdev_put+0x436/0x7f0 fs/block_dev.c:1791 blkdev_put+0x88/0x510 fs/block_dev.c:1856 kill_block_super+0xbd/0xf0 fs/super.c:1164 deactivate_locked_super+0x79/0xe0 fs/super.c:319 deactivate_super fs/super.c:350 [inline] deactivate_super+0x85/0xa0 fs/super.c:346 cleanup_mnt+0xb2/0x150 fs/namespace.c:1183 __cleanup_mnt+0x16/0x20 fs/namespace.c:1190 task_work_run+0x119/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 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+0x4a9/0x630 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458da9 RSP: 002b:00007f697dce1c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 0e00000000000000 RDI: 0000000020000280 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f697dce26d4 R13: 00000000004c7e35 R14: 00000000004de060 R15: 00000000ffffffff INFO: task syz-executor.3:8649 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29184 8649 7101 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d41 RSP: 002b:00007f697dc7ea80 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000020000068 RCX: 0000000000412d41 RDX: 00007f697dc7eb0a RSI: 0000000000000002 RDI: 00007f697dc7eb00 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000005 R13: 00000000004c79d9 R14: 00000000004dda18 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541 2 locks held by getty/7053: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7054: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7055: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7056: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7057: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7058: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7059: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/7094: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa6/0x7f0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1e/0x1b0 drivers/block/loop.c:1667 2 locks held by syz-executor.5/7096: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/7099: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by syz-executor.1/7738: #0: (&bdev->bd_mutex){+.+.}, at: [] iterate_bdevs+0xc4/0x263 fs/block_dev.c:2166 1 lock held by syz-executor.1/7819: #0: (&bdev->bd_mutex){+.+.}, at: [] iterate_bdevs+0xc4/0x263 fs/block_dev.c:2166 1 lock held by syz-executor.2/8632: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 1 lock held by syz-executor.2/8646: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 2 locks held by syz-executor.1/8629: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 3 locks held by syz-executor.3/8630: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa6/0x7f0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1e/0x1b0 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 1 lock held by syz-executor.3/8649: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 2 locks held by blkid/8637: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by blkid/8641: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 2 locks held by blkid/8643: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by blkid/8644: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1008 Comm: khungtaskd Not tainted 4.14.114 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x19c lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 78 Comm: kworker/u4:3 Not tainted 4.14.114 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a98b84c0 task.stack: ffff8880a98c0000 RIP: 0010:debug_lockdep_rcu_enabled.part.0+0xb/0x60 kernel/rcu/update.c:297 RSP: 0018:ffff8880a98c7c58 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffff888092c1b8a0 RCX: 1ffffffff0f56424 RDX: 0000000000000004 RSI: ffffffff869d1e40 RDI: ffff8880aee2394c RBP: ffff8880a98c7c68 R08: 0000000000000000 R09: ffff8880a98b8db0 R10: ffff8880a98b8d90 R11: ffff8880a98b84c0 R12: 0000000000000000 R13: ffff88809c22f2c0 R14: ffff8880633d9400 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002236000 CR3: 00000000950cd000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:683 [inline] batadv_nc_process_nc_paths.part.0+0x1e8/0x350 net/batman-adv/network-coding.c:707 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:687 [inline] batadv_nc_worker+0x54f/0x6d0 net/batman-adv/network-coding.c:742 process_one_work+0x868/0x1610 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Code: 00 00 00 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 57 ff ff ff 5d c3 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 <48> 89 e5 53 65 48 8b 1c 25 40 ee 01 00 48 8d bb 7c 08 00 00 48