INFO: task syz-executor.5:1870 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25008 1870 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffc71ba7008 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00000000000595ee RCX: 00000000004143b0 RDX: 00007ffc71ba709a RSI: 0000000000000002 RDI: 00007ffc71ba7090 RBP: 000000000000045b R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc71ba7040 R14: 000000000005950c R15: 00007ffc71ba7050 INFO: task syz-executor.4:14608 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25312 14608 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffc50bcfad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000059519 RCX: 00000000004143b0 RDX: 00007ffc50bcfb6a RSI: 0000000000000002 RDI: 00007ffc50bcfb60 RBP: 00000000000001a8 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc50bcfb10 R14: 000000000005950a R15: 00007ffc50bcfb20 INFO: task syz-executor.3:19397 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25312 19397 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffc4da87d48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000005983f RCX: 00000000004143b0 RDX: 00007ffc4da87dda RSI: 0000000000000002 RDI: 00007ffc4da87dd0 RBP: 00000000000000b0 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4da87d80 R14: 0000000000059515 R15: 00007ffc4da87d90 INFO: task syz-executor.0:21526 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28928 21526 17873 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183 loop_set_status64+0xa5/0x100 drivers/block/loop.c:1301 lo_ioctl+0xd1/0x1a30 drivers/block/loop.c:1431 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x8d0/0x1870 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a4a7 RSP: 002b:00007f9946eb09f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9946eb16d4 RCX: 000000000045a4a7 RDX: 00007f9946eb0ab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000004 R15: 00000000ffffffff INFO: task syz-executor.0:21545 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28912 21545 17873 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 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/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143d1 RSP: 002b:00007f9946e6e9f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f9946e6f6d4 RCX: 00000000004143d1 RDX: 00007f9946e6ebaa RSI: 0000000000000002 RDI: 00007f9946e6eba0 RBP: 000000000075c070 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000003 R14: 00000000004e2228 R15: 00000000ffffffff INFO: task syz-executor.2:21533 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28768 21533 21097 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 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/0x710 fs/file_table.c:210 task_work_run+0x125/0x1a0 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:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x3a3/0x520 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4141d1 RSP: 002b:00007fbebdae1a80 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007fbebdae1b40 RCX: 00000000004141d1 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000005 RBP: 0000000000000002 R08: 00007fbebdae1b40 R09: 00007fbebdae1ae0 R10: 0000000000042000 R11: 0000000000000293 R12: 0000000000000004 R13: 00000000004c9fe9 R14: 00000000004e1d18 R15: 00000000ffffffff INFO: task syz-executor.2:21541 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27872 21541 21097 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 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/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143d1 RSP: 002b:00007fbebdac0a80 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00000000004143d1 RDX: 00007fbebdac0b0a RSI: 0000000000000002 RDI: 00007fbebdac0b00 RBP: 0000000000000002 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000293 R12: 0000000000000004 R13: 00000000004c9fe9 R14: 00000000004e1d18 R15: 00000000ffffffff INFO: task blkid:21532 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28832 21532 19331 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 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/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7faf8399e120 RSP: 002b:00007fffda176308 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faf8399e120 RDX: 00007fffda177f41 RSI: 0000000000000000 RDI: 00007fffda177f41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001976030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:21534 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28992 21534 20151 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7fd3babc2120 RSP: 002b:00007fffe1d7bc08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd3babc2120 RDX: 00007fffe1d7df34 RSI: 0000000000000000 RDI: 00007fffe1d7df34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000024bc030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task syz-executor.1:21538 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28624 21538 20774 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a639 RSP: 002b:00007fe1b6445c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe1b64466d4 R13: 00000000004c4080 R14: 00000000004d8418 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<0000000046829898>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1766: #0: (&tty->ldisc_sem){++++}, at: [<00000000c342eef3>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003d8ca3a0>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.5/1870: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/14608: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.3/19397: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.0/21526: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<000000004beea5a7>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000654e34be>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 1 lock held by syz-executor.0/21545: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 1 lock held by syz-executor.2/21533: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000a2c6caaf>] blkdev_put+0x27/0x4c0 fs/block_dev.c:1814 1 lock held by syz-executor.2/21541: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 2 locks held by blkid/21532: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by blkid/21534: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.1/21538: #0: (loop_index_mutex){+.+.}, at: [<00000000da650ac4>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<0000000045c6406d>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 1 lock held by syz-executor.1/21542: #0: (loop_index_mutex){+.+.}, at: [<00000000da650ac4>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.1/21559: #0: (loop_index_mutex){+.+.}, at: [<00000000da650ac4>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 1 lock held by syz-executor.1/21563: #0: (loop_index_mutex){+.+.}, at: [<00000000da650ac4>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 2 locks held by blkid/21537: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000d02183d5>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000aaa06f70>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.155-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe5/0x154 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x119/0x147 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x629/0xbe0 kernel/hung_task.c:274 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1636 Comm: rs:main Q:Reg Not tainted 4.14.155-syzkaller #0 task: 00000000eda6ac9b task.stack: 000000001015dfab RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:111 [inline] RIP: 0010:unwind_next_frame+0x56c/0x1810 arch/x86/kernel/unwind_orc.c:348 RSP: 0018:ffff8881c377f558 EFLAGS: 00000a02 RAX: 000000000000b354 RBX: ffff8881c377f628 RCX: 000000000000b354 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffffb446e5e0 RBP: 1ffff110386efeb2 R08: 0000000000000001 R09: ffff8881c377fa30 R10: ffff8881c377f65d R11: 000000000001c033 R12: ffffffffb23354fa R13: ffff8881c377f660 R14: ffff8881c377f670 R15: 0000000000000001 FS: 00007fde61dea700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001bfa000 CR3: 00000001d6e22006 CR4: 00000000001606a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/common.c:76 [inline] set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc.part.0+0x53/0xc0 mm/kasan/common.c:501 slab_post_alloc_hook mm/slab.h:439 [inline] slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2800 [inline] kmem_cache_alloc+0xee/0x360 mm/slub.c:2805 mempool_alloc+0x126/0x300 mm/mempool.c:330 bio_alloc_bioset+0x379/0x660 block/bio.c:486 bio_alloc include/linux/bio.h:422 [inline] blkdev_issue_flush+0xeb/0x320 block/blk-flush.c:527 ext4_sync_file+0xb2f/0x1250 fs/ext4/fsync.c:157 vfs_fsync_range+0x106/0x260 fs/sync.c:196 generic_write_sync include/linux/fs.h:2713 [inline] ext4_file_write_iter+0x883/0xdb0 fs/ext4/file.c:279 call_write_iter include/linux/fs.h:1798 [inline] new_sync_write fs/read_write.c:471 [inline] __vfs_write+0x401/0x5a0 fs/read_write.c:484 vfs_write+0x17f/0x4d0 fs/read_write.c:546 SYSC_write fs/read_write.c:594 [inline] SyS_write+0x102/0x250 fs/read_write.c:586 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7fde6384819d RSP: 002b:00007fde61de9000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000091 RCX: 00007fde6384819d RDX: 0000000000000091 RSI: 0000000001beaa90 RDI: 0000000000000005 RBP: 0000000001beaa90 R08: 0000000001c150d0 R09: 656c6c616b7a7973 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fde61de9480 R14: 0000000000000002 R15: 0000000001bea890 Code: 41 8d 53 ff 39 d0 0f 83 9c 02 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d 3c 8d 90 18 44 b4 48 89 fe 48 c1 ee 03 0f b6 34 16 <48> 89 fa 83 e2 07 83 c2 03 40 38 f2 7c 09 40 84 f6 0f 85 29 0e