bond0 (unregistering): Releasing backup interface bridge1110 bond0 (unregistering): Releasing backup interface bridge1109 bond0 (unregistering): Releasing backup interface bridge1108 bond0 (unregistering): Releasing backup interface bridge1107 INFO: task kworker/1:2:27297 blocked for more than 140 seconds. Not tainted 4.19.86-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:2 D27376 27297 2 0x80000000 kobject: 'rx-0' (00000000bf082dd1): kobject_cleanup, parent 000000001aac7046 Workqueue: events switchdev_deferred_process_work kobject: 'rx-0' (00000000bf082dd1): auto cleanup 'remove' event Call Trace: kobject: 'rx-0' (00000000bf082dd1): kobject_uevent_env context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 kobject: 'rx-0' (00000000bf082dd1): kobject_uevent_env: uevent_suppress caused the event to drop! kobject: 'rx-0' (00000000bf082dd1): auto cleanup kobject_del kobject: 'rx-0' (00000000bf082dd1): calling ktype release kobject: 'rx-0': free name kobject: 'tx-0' (00000000d2dc7e66): kobject_cleanup, parent 000000001aac7046 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 kobject: 'tx-0' (00000000d2dc7e66): auto cleanup 'remove' event kobject: 'tx-0' (00000000d2dc7e66): kobject_uevent_env rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 kobject: 'tx-0' (00000000d2dc7e66): kobject_uevent_env: uevent_suppress caused the event to drop! switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:150 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 kobject: 'tx-0' (00000000d2dc7e66): auto cleanup kobject_del kobject: 'tx-0' (00000000d2dc7e66): calling ktype release ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 kobject: 'tx-0': free name INFO: task kworker/0:0:32503 blocked for more than 140 seconds. kobject: 'queues' (000000001aac7046): kobject_cleanup, parent (null) Not tainted 4.19.86-syzkaller #0 kobject: 'queues' (000000001aac7046): calling ktype release "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kobject: 'queues' (000000001aac7046): kset_release kworker/0:0 D kobject: 'queues': free name 27072 32503 2 0x80000000 kobject: 'bridge1107' (00000000a0842565): kobject_uevent_env Workqueue: events linkwatch_event kobject: 'bridge1107' (00000000a0842565): kobject_uevent_env: uevent_suppress caused the event to drop! kobject: 'bonding_slave' (000000009758e8a5): kobject_cleanup, parent 00000000211fb506 Call Trace: kobject: 'bonding_slave' (000000009758e8a5): does not have a release() function, it is broken and must be fixed. context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 kobject: 'bonding_slave' (000000009758e8a5): auto cleanup kobject_del kobject: 'bonding_slave': free name schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 linkwatch_event+0xf/0x70 net/core/link_watch.c:236 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 INFO: task syz-executor.4:32609 blocked for more than 140 seconds. bond0 (unregistering): Releasing backup interface bridge1106 Not tainted 4.19.86-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28216 32609 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock net/core/rtnetlink.c:77 [inline] rtnetlink_rcv_msg+0x40a/0xb00 net/core/rtnetlink.c:4744 netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908 net_ratelimit: 12 callbacks suppressed protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 protocol 88fb is buggy, dev hsr_slave_0 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:632 protocol 88fb is buggy, dev hsr_slave_1 __sys_sendto+0x262/0x380 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1795 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414373 Code: c3 66 0f 1f 44 00 00 41 54 55 53 48 89 fb 48 83 ec 10 0f bf 47 4a 48 0f bf d0 89 c1 8b 47 54 48 03 57 68 29 c8 83 f8 01 89 44 <24> 04 b8 90 f7 ff ff 48 89 54 24 08 0f 8e e7 01 00 00 80 3a 31 0f RSP: 002b:00007fff4c181e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000a72200 RCX: 0000000000414373 RDX: 0000000000000028 RSI: 0000000000a72250 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff4c181e70 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000a72250 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/1038: #0: 000000009066cf68 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 4 locks held by kworker/u4:4/2285: #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000dbbd674b ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 0000000017f8afa7 (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 000000006911211f (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x970 net/core/net_namespace.c:520 #3: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by rsyslogd/7527: 2 locks held by getty/7649: #0: 0000000038131932 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000041f8e196 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7650: #0: 000000006925be0c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b2f0838f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7651: #0: 000000002930a8b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000002dba235e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7652: #0: 00000000664dbba0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 #1: 0000000004d03fc3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7653: #0: 0000000016c3b366 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000c2379740 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7654: #0: 000000006e5510e9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000009d7b06d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7655: #0: 00000000a2fefc43 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000bc640d96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 3 locks held by kworker/1:2/27297: #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 00000000158131ab (deferred_process_work){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/0:3/7486: #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000d439fbdc ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 0000000077ff8f2e ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/0:0/32503: protocol 88fb is buggy, dev hsr_slave_0 protocol 88fb is buggy, dev hsr_slave_1 #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000adc86a45 ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 00000000ffba2ea9 ((linkwatch_work).work){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor.4/32609: #0: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000ef11e8f5 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40a/0xb00 net/core/rtnetlink.c:4744 ============================================= kobject: 'batman_adv' (00000000953ff329): kobject_uevent_env NMI backtrace for cpu 1 CPU: 1 PID: 1038 Comm: khungtaskd Not tainted 4.19.86-syzkaller #0 kobject: 'batman_adv' (00000000953ff329): kobject_uevent_env: filter function caused the event to drop! Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: kobject: 'batman_adv' (00000000953ff329): kobject_cleanup, parent (null) __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 kobject: 'batman_adv' (00000000953ff329): calling ktype release trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: kobject: (00000000953ff329): dynamic_kobj_release NMI backtrace for cpu 0 CPU: 0 PID: 2285 Comm: kworker/u4:4 Not tainted 4.19.86-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__save_stack_trace+0x8d/0x100 arch/x86/kernel/stacktrace.c:45 Code: d2 75 27 eb 39 44 89 e2 48 89 df e8 2d ff ff ff 85 c0 75 2a 48 8d bd 78 ff ff ff e8 3d 32 07 00 8b 85 78 ff ff ff 85 c0 74 14 <48> 8d bd 78 ff ff ff e8 67 20 07 00 48 85 c0 48 89 c6 75 c7 8b 03 RSP: 0018:ffff8880ae807ab0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8880ae807b58 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 1ffff11015d00f00 RDI: ffff8880ae807af8 RBP: ffff8880ae807b38 R08: 0000000000000001 R09: ffff8880ae807b08 R10: ffff8880ae807ad8 R11: ffff8880ae807ae8 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880a182c600 R15: 0000000000000040 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000094ca4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60 save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 __rcu_reclaim kernel/rcu/rcu.h:231 [inline] rcu_do_batch kernel/rcu/tree.c:2584 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline] rcu_process_callbacks+0xcb6/0x1a30 kernel/rcu/tree.c:2881 __do_softirq+0x25c/0x921 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1696 [inline] RIP: 0010:vprintk_emit+0x5b8/0x690 kernel/printk/printk.c:1933 Code: 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 0f 85 a2 00 00 00 48 83 3d 1c e9 1c 07 00 74 29 e8 fd ac 15 00 48 89 df 57 9d <0f> 1f 44 00 00 e9 79 fe ff ff e8 e9 ac 15 00 0f 0b e8 e2 ac 15 00 RSP: 0018:ffff8880a1fb76b0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a182c600 RBX: 0000000000000293 RCX: 1ffff110143059e3 RDX: 0000000000000000 RSI: ffffffff81557273 RDI: 0000000000000293 RBP: ffff8880a1fb76f8 R08: ffff8880a182c600 R09: ffff8880a182cf18 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000031 R13: 1ffffffff10e4b71 R14: 0000000000000200 R15: ffff8880a8232600 vprintk_default+0x28/0x30 kernel/printk/printk.c:1975 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2008 dynamic_kobj_release+0x24/0x30 lib/kobject.c:715 kobject_cleanup lib/kobject.c:662 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put.cold+0x289/0x2e6 lib/kobject.c:708 batadv_sysfs_del_hardif+0x6f/0xc0 net/batman-adv/sysfs.c:1205 batadv_hardif_remove_interface.constprop.0+0x85/0x180 net/batman-adv/hard-interface.c:978 batadv_hard_if_event+0x285/0xf60 net/batman-adv/hard-interface.c:1055 notifier_call_chain+0xc2/0x230 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1747 call_netdevice_notifiers net/core/dev.c:1765 [inline] rollback_registered_many+0x894/0xda0 net/core/dev.c:8019 unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9129 unregister_netdevice_many net/core/dev.c:9128 [inline] default_device_exit_batch+0x34e/0x410 net/core/dev.c:9600 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:156 cleanup_net+0x404/0x970 net/core/net_namespace.c:553 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415