INFO: task kworker/0:20:13713 blocked for more than 143 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:20 state:D stack:25048 pid:13713 ppid: 2 flags:0x00004000 Workqueue: events switchdev_deferred_process_work Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 INFO: task kworker/0:46:18694 blocked for more than 143 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:46 state:D stack:24632 pid:18694 ppid: 2 flags:0x00004000 Workqueue: events linkwatch_event Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 linkwatch_event+0xa/0x50 net/core/link_watch.c:251 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 INFO: task syz-executor.0:22951 blocked for more than 144 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20320 pid:22951 ppid: 20175 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 tun_detach drivers/net/tun.c:699 [inline] tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 __fput+0x3bf/0x890 fs/file_table.c:280 task_work_run+0x129/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0x6a3/0x2480 kernel/exit.c:872 do_group_exit+0x144/0x310 kernel/exit.c:994 get_signal+0xc66/0x14e0 kernel/signal.c:2889 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314 exc_general_protection+0x358/0x4f0 arch/x86/kernel/traps.c:562 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:562 RIP: 0033:0x7fe6bfaa5db1 RSP: 002b:0000000020000240 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fe6bfbd3f80 RCX: 00007fe6bfaa5da9 RDX: 0000000020000280 RSI: 0000000020000240 RDI: 0000000088800080 RBP: 00007fe6bfaf247a R08: 0000000020000300 R09: 0000000020000300 R10: 00000000200002c0 R11: 0000000000000202 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe6bfbd3f80 R15: 00007ffca57e1df8 INFO: task syz-executor.1:23382 blocked for more than 144 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:27168 pid:23382 ppid: 22319 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 tun_detach drivers/net/tun.c:699 [inline] tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 __fput+0x3bf/0x890 fs/file_table.c:280 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:175 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f817c106c9a RSP: 002b:00007ffd2f0eda90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f817c106c9a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f817c237980 R08: 0000001b2e320000 R09: 0000000000000006 R10: 0000000081a6f1eb R11: 0000000000000293 R12: 00000000001e4d75 R13: ffffffffffffffff R14: 00007f817bc8a000 R15: 00000000001e4a34 INFO: task syz-executor.2:23434 blocked for more than 145 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27064 pid:23434 ppid: 1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 rtnl_lock net/core/rtnetlink.c:72 [inline] rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2505 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x564/0x720 net/socket.c:2058 __do_sys_sendto net/socket.c:2070 [inline] __se_sys_sendto net/socket.c:2066 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2066 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f986b2e2a9c RSP: 002b:00007ffecb0d14c0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f986bf37620 RCX: 00007f986b2e2a9c RDX: 0000000000000028 RSI: 00007f986bf37670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffecb0d1514 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f986bf37670 R15: 0000000000000000 Showing all locks held in the system: 5 locks held by kworker/u4:0/9: #0: ffff888011dcd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90000ce7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9cfe50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:558 #3: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11576 [inline] #3: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x1ac/0x3f0 net/core/dev.c:11614 #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 1 lock held by khungtaskd/27: #0: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3265: #0: ffff8880251c5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 3 locks held by kworker/u4:5/3636: 4 locks held by kworker/u4:9/8030: #0: ffff888014384938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90004107d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff8880253b0bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1f6/0x3d10 fs/ext4/inode.c:2677 #3: ffff8880253b2990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x12b9/0x1570 fs/jbd2/transaction.c:462 3 locks held by kworker/0:20/13713: #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900054d7d20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74 3 locks held by kworker/0:35/18681: #0: ffff888024063d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90004777d20 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4655 2 locks held by kworker/0:36/18682: #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90004897d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 3 locks held by kworker/0:46/18694: #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900049a7d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251 3 locks held by kworker/0:48/18696: #0: ffff888011c71938 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900049d7d20 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x7f/0xb70 net/wireless/reg.c:2436 3 locks held by syz-executor.4/20158: 3 locks held by syz-executor.2/22906: #0: ffff8880253ae460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x1825/0x31e0 fs/coredump.c:825 #1: ffff88808e0cd3b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline] #1: ffff88808e0cd3b0 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa0/0x360 fs/ext4/file.c:262 #2: ffff8880253ae0e0 (&type->s_umount_key#32){++++}-{3:3}, at: try_to_writeback_inodes_sb+0x1d/0xb0 fs/fs-writeback.c:2729 1 lock held by syz-executor.0/22951: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 1 lock held by syz-executor.1/23382: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 1 lock held by syz-executor.2/23434: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.0/23491: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.1/23492: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.4/23533: 2 locks held by syz-executor.4/23541: 2 locks held by syz-executor.3/23549: 2 locks held by syz-executor.4/23559: 1 lock held by syz-executor.3/23565: 3 locks held by syz-executor.4/23575: 1 lock held by syz-executor.3/23586: 3 locks held by syz-executor.4/23596: 3 locks held by syz-executor.3/23606: 1 lock held by syz-executor.4/23613: 2 locks held by syz-executor.4/23621: 2 locks held by syz-executor.3/23629: 3 locks held by syz-executor.4/23635: 1 lock held by syz-executor.4/23639: 1 lock held by syz-executor.4/23661: 2 locks held by syz-executor.4/23728: 3 locks held by syz-executor.4/23737: 1 lock held by syz-executor.2/23785: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.3/23870: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 2 locks held by syz-executor.4/23876: 2 locks held by syz-executor.4/23888: 2 locks held by syz-executor.4/23894: 2 locks held by syz-executor.4/23900: 2 locks held by syz-executor.4/23908: 1 lock held by syz-executor.1/23912: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.0/23913: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 3 locks held by syz-executor.4/23920: 4 locks held by syz-executor.4/23925: 2 locks held by syz-executor.4/23938: 3 locks held by syz-executor.4/23943: 2 locks held by syz-executor.4/23953: 1 lock held by syz-executor.3/23955: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 2 locks held by syz-executor.4/23982: 2 locks held by syz-executor.4/23990: 1 lock held by syz-executor.2/24022: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 1 lock held by syz-executor.4/24044: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3636 Comm: kworker/u4:5 Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Workqueue: phy82 ieee80211_iface_work RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:193 Code: 1f 84 00 00 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 18 56 63 0c 48 89 de 5b e9 57 e5 48 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d e4 35 82 7e 65 8b 15 e5 35 82 7e f7 c2 00 RSP: 0018:ffffc90004127a78 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88807bcd0000 RDX: ffff88807bcd0000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff89aab23a R09: fffff52000824f49 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff88808a900000 R14: ffff888084c3dad0 R15: ffff88801a228da0 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fab0d1b96c6 CR3: 0000000071bb4000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sdata_assert_lock net/mac80211/ieee80211_i.h:1050 [inline] ieee80211_sta_active_ibss+0x97/0x2d0 net/mac80211/ibss.c:656 ieee80211_sta_merge_ibss net/mac80211/ibss.c:1308 [inline] ieee80211_ibss_work+0x857/0x1480 net/mac80211/ibss.c:1713 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298