INFO: task syz-executor678:8007 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D27384 8007 8005 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 bd_prepare_to_claim fs/block_dev.c:1078 [inline] bd_start_claiming fs/block_dev.c:1149 [inline] bd_prepare_to_claim fs/block_dev.c:1078 [inline] fs/block_dev.c:1604 bd_start_claiming fs/block_dev.c:1149 [inline] fs/block_dev.c:1604 blkdev_get+0x3ee/0x890 fs/block_dev.c:1604 fs/block_dev.c:1604 blkdev_get_by_path+0x38/0xa0 fs/block_dev.c:1692 fs/block_dev.c:1692 mount_bdev+0x4c/0x360 fs/super.c:1092 fs/super.c:1092 mount_fs+0x92/0x2a0 fs/super.c:1237 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] vfs_kern_mount fs/namespace.c:1036 [inline] fs/namespace.c:2902 do_new_mount fs/namespace.c:2572 [inline] fs/namespace.c:2902 do_mount+0xe65/0x2a10 fs/namespace.c:2902 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SYSC_mount fs/namespace.c:3118 [inline] fs/namespace.c:3095 SyS_mount+0xa8/0x120 fs/namespace.c:3095 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9579 RSP: 002b:00007fff88938738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff88938770 RCX: 00007f6e55bd9579 RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000020000080 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 0000000000000000 R14: 00007fff8893875c R15: 00007fff88938760 INFO: task syz-executor678:8010 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D27200 8010 8006 0x80000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock_common kernel/locking/mutex.c:833 [inline] kernel/locking/mutex.c:893 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 kernel/locking/mutex.c:893 lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 drivers/block/loop.c:1414 __blkdev_driver_ioctl block/ioctl.c:297 [inline] __blkdev_driver_ioctl block/ioctl.c:297 [inline] block/ioctl.c:594 blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block/ioctl.c:594 ioctl_by_bdev+0xa0/0x110 fs/block_dev.c:2092 fs/block_dev.c:2092 udf_get_last_session+0x7c/0xd0 fs/udf/lowlevel.c:37 fs/udf/lowlevel.c:37 udf_fill_super+0x11e6/0x1660 fs/udf/super.c:2159 fs/udf/super.c:2159 mount_bdev+0x2b3/0x360 fs/super.c:1134 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] vfs_kern_mount fs/namespace.c:1036 [inline] fs/namespace.c:2902 do_new_mount fs/namespace.c:2572 [inline] fs/namespace.c:2902 do_mount+0xe65/0x2a10 fs/namespace.c:2902 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SYSC_mount fs/namespace.c:3118 [inline] fs/namespace.c:3095 SyS_mount+0xa8/0x120 fs/namespace.c:3095 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9579 RSP: 002b:00007fff88938738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff88938770 RCX: 00007f6e55bd9579 RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000020000080 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 0000000000000000 R14: 00007fff8893875c R15: 00007fff88938760 INFO: task syz-executor678:8019 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D28912 8019 8016 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] kernel/locking/rwsem-xadd.c:309 rwsem_down_read_failed+0x1e6/0x350 kernel/locking/rwsem-xadd.c:309 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] __down_read arch/x86/include/asm/rwsem.h:66 [inline] kernel/locking/rwsem.c:26 down_read+0x44/0x80 kernel/locking/rwsem.c:26 kernel/locking/rwsem.c:26 __get_super.part.0+0x271/0x390 fs/super.c:678 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] __get_super include/linux/spinlock.h:317 [inline] fs/super.c:707 get_super+0x2b/0x50 fs/super.c:707 fs/super.c:707 fsync_bdev+0x14/0xc0 fs/block_dev.c:495 fs/block_dev.c:495 invalidate_partition+0x74/0xb0 block/genhd.c:1509 block/genhd.c:1509 drop_partitions.isra.0+0x83/0x150 block/partition-generic.c:442 block/partition-generic.c:442 rescan_partitions+0xa9/0x800 block/partition-generic.c:515 block/partition-generic.c:515 __blkdev_reread_part+0x140/0x1d0 block/ioctl.c:173 block/ioctl.c:173 blkdev_reread_part+0x23/0x40 block/ioctl.c:193 block/ioctl.c:193 loop_reread_partitions drivers/block/loop.c:624 [inline] loop_reread_partitions drivers/block/loop.c:624 [inline] drivers/block/loop.c:1193 loop_set_status+0xeeb/0x12b0 drivers/block/loop.c:1193 drivers/block/loop.c:1193 loop_set_status64+0x92/0xe0 drivers/block/loop.c:1311 drivers/block/loop.c:1311 lo_ioctl+0x587/0x1cd0 drivers/block/loop.c:1441 drivers/block/loop.c:1441 __blkdev_driver_ioctl block/ioctl.c:297 [inline] __blkdev_driver_ioctl block/ioctl.c:297 [inline] block/ioctl.c:594 blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] vfs_ioctl fs/ioctl.c:46 [inline] fs/ioctl.c:684 file_ioctl fs/ioctl.c:500 [inline] fs/ioctl.c:684 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SYSC_ioctl fs/ioctl.c:701 [inline] fs/ioctl.c:692 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9427 RSP: 002b:00007fff889384d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fff88938500 RCX: 00007f6e55bd9427 RDX: 00007fff88938610 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 0000000000000004 R08: 00007fff88938370 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 R13: 0000555556554384 R14: 00007fff88938610 R15: 00007fff88938760 INFO: task syz-executor678:8020 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D27544 8020 8018 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock_common kernel/locking/mutex.c:833 [inline] kernel/locking/mutex.c:893 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 kernel/locking/mutex.c:893 __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 fs/block_dev.c:1455 blkdev_get+0x441/0x890 fs/block_dev.c:1611 fs/block_dev.c:1611 blkdev_get_by_path+0x38/0xa0 fs/block_dev.c:1692 fs/block_dev.c:1692 mount_bdev+0x4c/0x360 fs/super.c:1092 fs/super.c:1092 mount_fs+0x92/0x2a0 fs/super.c:1237 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] vfs_kern_mount fs/namespace.c:1036 [inline] fs/namespace.c:2902 do_new_mount fs/namespace.c:2572 [inline] fs/namespace.c:2902 do_mount+0xe65/0x2a10 fs/namespace.c:2902 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SYSC_mount fs/namespace.c:3118 [inline] fs/namespace.c:3095 SyS_mount+0xa8/0x120 fs/namespace.c:3095 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9579 RSP: 002b:00007fff88938738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff88938770 RCX: 00007f6e55bd9579 RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000020000080 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 0000000000000000 R14: 00007fff8893875c R15: 00007fff88938760 INFO: task syz-executor678:8021 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D27544 8021 8015 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 bd_prepare_to_claim fs/block_dev.c:1078 [inline] bd_start_claiming fs/block_dev.c:1149 [inline] bd_prepare_to_claim fs/block_dev.c:1078 [inline] fs/block_dev.c:1604 bd_start_claiming fs/block_dev.c:1149 [inline] fs/block_dev.c:1604 blkdev_get+0x3ee/0x890 fs/block_dev.c:1604 fs/block_dev.c:1604 blkdev_get_by_path+0x38/0xa0 fs/block_dev.c:1692 fs/block_dev.c:1692 mount_bdev+0x4c/0x360 fs/super.c:1092 fs/super.c:1092 mount_fs+0x92/0x2a0 fs/super.c:1237 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] vfs_kern_mount fs/namespace.c:1036 [inline] fs/namespace.c:2902 do_new_mount fs/namespace.c:2572 [inline] fs/namespace.c:2902 do_mount+0xe65/0x2a10 fs/namespace.c:2902 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SYSC_mount fs/namespace.c:3118 [inline] fs/namespace.c:3095 SyS_mount+0xa8/0x120 fs/namespace.c:3095 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9579 RSP: 002b:00007fff88938738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff88938770 RCX: 00007f6e55bd9579 RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000020000080 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 0000000000000000 R14: 00007fff8893875c R15: 00007fff88938760 INFO: task syz-executor678:8022 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor678 D27544 8022 8017 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 bd_prepare_to_claim fs/block_dev.c:1078 [inline] bd_start_claiming fs/block_dev.c:1149 [inline] bd_prepare_to_claim fs/block_dev.c:1078 [inline] fs/block_dev.c:1604 bd_start_claiming fs/block_dev.c:1149 [inline] fs/block_dev.c:1604 blkdev_get+0x3ee/0x890 fs/block_dev.c:1604 fs/block_dev.c:1604 blkdev_get_by_path+0x38/0xa0 fs/block_dev.c:1692 fs/block_dev.c:1692 mount_bdev+0x4c/0x360 fs/super.c:1092 fs/super.c:1092 mount_fs+0x92/0x2a0 fs/super.c:1237 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] vfs_kern_mount fs/namespace.c:1036 [inline] fs/namespace.c:2902 do_new_mount fs/namespace.c:2572 [inline] fs/namespace.c:2902 do_mount+0xe65/0x2a10 fs/namespace.c:2902 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SYSC_mount fs/namespace.c:3118 [inline] fs/namespace.c:3095 SyS_mount+0xa8/0x120 fs/namespace.c:3095 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f6e55bd9579 RSP: 002b:00007fff88938738 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff88938770 RCX: 00007f6e55bd9579 RDX: 0000000020000040 RSI: 0000000020000140 RDI: 0000000020000080 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000f4240 R13: 0000000000000000 R14: 00007fff8893875c R15: 00007fff88938760 INFO: task systemd-udevd:8044 blocked for more than 140 seconds. Not tainted 4.14.258-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28912 8044 4627 0x00000104 Call Trace: context_switch kernel/sched/core.c:2811 [inline] context_switch kernel/sched/core.c:2811 [inline] kernel/sched/core.c:3387 __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock_common kernel/locking/mutex.c:833 [inline] kernel/locking/mutex.c:893 __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 kernel/locking/mutex.c:893 __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 fs/block_dev.c:1455 blkdev_get+0x88/0x890 fs/block_dev.c:1611 fs/block_dev.c:1611 blkdev_open+0x1cc/0x250 fs/block_dev.c:1772 fs/block_dev.c:1772 do_dentry_open+0x44b/0xec0 fs/open.c:777 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 fs/open.c:888 do_last fs/namei.c:3428 [inline] do_last fs/namei.c:3428 [inline] fs/namei.c:3569 path_openat+0x628/0x2970 fs/namei.c:3569 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f36c4bdf840 RSP: 002b:00007ffd87b65888 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000055a490895140 RCX: 00007f36c4bdf840 RDX: 000055a490061fe3 RSI: 00000000000a0800 RDI: 000055a49088e8f0 RBP: 00007ffd87b65a00 R08: 000055a490061670 R09: 0000000000000010 R10: 000055a490061d0c R11: 0000000000000246 R12: 00007ffd87b65950 R13: 000055a49088e7d0 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 kernel/locking/lockdep.c:4548 2 locks held by syz-executor678/8010: #0: (&type->s_umount_key#46/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#46/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] fs/super.c:516 #0: (&type->s_umount_key#46/1){+.+.}, at: [] sget_userns+0x556/0xc10 fs/super.c:516 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 drivers/block/loop.c:1414 3 locks held by syz-executor678/8019: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 drivers/block/loop.c:1414 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 block/ioctl.c:192 #2: (&type->s_umount_key#47){.+.+}, at: [] __get_super.part.0+0x271/0x390 fs/super.c:678 fs/super.c:678 1 lock held by syz-executor678/8020: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 fs/block_dev.c:1455 1 lock held by systemd-udevd/8044: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x191/0x1090 fs/block_dev.c:1455 fs/block_dev.c:1455 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.258-syzkaller #0 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 lib/dump_stack.c:17 [inline] lib/dump_stack.c:58 dump_stack+0x1b2/0x281 lib/dump_stack.c:58 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 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] trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] kernel/hung_task.c:274 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] kernel/hung_task.c:274 watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8 Comm: rcu_preempt Not tainted 4.14.258-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880b5420200 task.stack: ffff8880b5428000 RIP: 0010:mark_held_locks+0xb6/0xf0 kernel/locking/lockdep.c:2858 kernel/locking/lockdep.c:2858 RSP: 0018:ffff8880b542fc20 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880b5420200 RCX: 0000000000000000 RDX: 1ffff11016a84150 RSI: 0000000000000000 RDI: ffff8880b5420a80 RBP: ffffffff81485580 R08: ffffffff8b9c0bf0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000297 R13: ffff8880b5420200 R14: ffff8880b542fd18 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ac4857020 CR3: 00000000a102a000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:2875 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:2875 [inline] kernel/locking/lockdep.c:2930 trace_hardirqs_on_caller+0x288/0x580 kernel/locking/lockdep.c:2930 kernel/locking/lockdep.c:2930 del_timer_sync+0x1a0/0x240 kernel/time/timer.c:1238 kernel/time/timer.c:1238 schedule_timeout+0x4b7/0xe90 kernel/time/timer.c:1748 kernel/time/timer.c:1748 rcu_gp_kthread+0xc0a/0x1e60 kernel/rcu/tree.c:2255 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 arch/x86/entry/entry_64.S:404 Code: c0 75 4c 0f b6 46 22 44 89 e2 a8 03 0f 45 d5 a8 04 74 0c 4c 89 ef e8 0a ef ff ff 85 c0 74 11 83 c3 01 41 39 9d 80 08 00 00 7f af 01 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 89 ---------------- Code disassembly (best guess): 0: c0 75 4c 0f shlb $0xf,0x4c(%rbp) 4: b6 46 mov $0x46,%dh 6: 22 44 89 e2 and -0x1e(%rcx,%rcx,4),%al a: a8 03 test $0x3,%al c: 0f 45 d5 cmovne %ebp,%edx f: a8 04 test $0x4,%al 11: 74 0c je 0x1f 13: 4c 89 ef mov %r13,%rdi 16: e8 0a ef ff ff callq 0xffffef25 1b: 85 c0 test %eax,%eax 1d: 74 11 je 0x30 1f: 83 c3 01 add $0x1,%ebx 22: 41 39 9d 80 08 00 00 cmp %ebx,0x880(%r13) 29: 7f af jg 0xffffffda * 2b: b8 01 00 00 00 mov $0x1,%eax <-- trapping instruction 30: 48 83 c4 08 add $0x8,%rsp 34: 5b pop %rbx 35: 5d pop %rbp 36: 41 5c pop %r12 38: 41 5d pop %r13 3a: 41 5e pop %r14 3c: 41 5f pop %r15 3e: c3 retq 3f: 89 .byte 0x89 ---------------- Code disassembly (best guess): 0: c0 75 4c 0f shlb $0xf,0x4c(%rbp) 4: b6 46 mov $0x46,%dh 6: 22 44 89 e2 and -0x1e(%rcx,%rcx,4),%al a: a8 03 test $0x3,%al c: 0f 45 d5 cmovne %ebp,%edx f: a8 04 test $0x4,%al 11: 74 0c je 0x1f 13: 4c 89 ef mov %r13,%rdi 16: e8 0a ef ff ff callq 0xffffef25 1b: 85 c0 test %eax,%eax 1d: 74 11 je 0x30 1f: 83 c3 01 add $0x1,%ebx 22: 41 39 9d 80 08 00 00 cmp %ebx,0x880(%r13) 29: 7f af jg 0xffffffda * 2b: b8 01 00 00 00 mov $0x1,%eax <-- trapping instruction 30: 48 83 c4 08 add $0x8,%rsp 34: 5b pop %rbx 35: 5d pop %rbp 36: 41 5c pop %r12 38: 41 5d pop %r13 3a: 41 5e pop %r14 3c: 41 5f pop %r15 3e: c3 retq 3f: 89 .byte 0x89