INFO: task syz.7.645:10477 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.645 state:D stack:24576 pid:10477 tgid:10475 ppid:7889 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 io_schedule+0x80/0xe0 kernel/sched/core.c:7835 folio_wait_bit_common+0x6dd/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1159 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a3/0xde0 fs/jfs/jfs_metapage.c:753 dtSplitPage+0x791/0x37c0 fs/jfs/jfs_dtree.c:1471 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x10a4/0x5f10 fs/jfs/jfs_dtree.c:871 jfs_create+0x75b/0xb10 fs/jfs/namei.c:138 lookup_open fs/namei.c:4489 [inline] open_last_lookups fs/namei.c:4589 [inline] path_openat+0x13b4/0x38a0 fs/namei.c:4833 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_creat fs/open.c:1450 [inline] __se_sys_creat fs/open.c:1444 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1444 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62d251c819 RSP: 002b:00007f62d0776028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f62d2795fa0 RCX: 00007f62d251c819 RDX: 0000000000000000 RSI: 0000000000000044 RDI: 00002000000009c0 RBP: 00007f62d25b2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f62d2796038 R14: 00007f62d2795fa0 R15: 00007ffd27765ea8 INFO: task syz.7.645:10497 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.645 state:D stack:25952 pid:10497 tgid:10475 ppid:7889 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2929 [inline] start_dirop fs/namei.c:2940 [inline] filename_create+0x200/0x370 fs/namei.c:4928 filename_mknodat+0x18c/0x670 fs/namei.c:5136 __do_sys_mknod fs/namei.c:5185 [inline] __se_sys_mknod+0x3a/0x150 fs/namei.c:5182 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62d251c819 RSP: 002b:00007f62d0755028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f62d2796090 RCX: 00007f62d251c819 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 000020000001f480 RBP: 00007f62d25b2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f62d2796128 R14: 00007f62d2796090 R15: 00007ffd27765ea8 INFO: task syz.7.645:10498 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.645 state:D stack:29024 pid:10498 tgid:10475 ppid:7889 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2929 [inline] start_dirop fs/namei.c:2940 [inline] filename_create+0x200/0x370 fs/namei.c:4928 filename_mkdirat+0xd2/0x520 fs/namei.c:5265 __do_sys_mkdirat fs/namei.c:5293 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5290 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62d251b687 RSP: 002b:00007f62d0733e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f62d0733ee0 RCX: 00007f62d251b687 RDX: 00000000000001ff RSI: 0000200000000580 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000580 R13: 00007f62d0733ea0 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz.7.645:10499 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.645 state:D stack:28224 pid:10499 tgid:10475 ppid:7889 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4586 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4833 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_creat fs/open.c:1450 [inline] __se_sys_creat fs/open.c:1444 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1444 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62d251c819 RSP: 002b:00007f62d0311028 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007f62d2796270 RCX: 00007f62d251c819 RDX: 0000000000000000 RSI: 000000000000010d RDI: 0000200000002e80 RBP: 00007f62d25b2c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f62d2796308 R14: 00007f62d2796270 R15: 00007ffd27765ea8 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801aee1138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f14ed20 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/42: #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000b37c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000b37c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 3 locks held by kworker/1:1/49: #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c07938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000bb7c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000bb7c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u8:4/67: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000152fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000152fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 4 locks held by kworker/u8:8/173: #0: ffff88801f2bf938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801f2bf938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90003b6fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90003b6fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff88803bc0c0d0 (&type->s_umount_key#73){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff88805f66a8e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 3 locks held by kworker/u8:11/1165: 3 locks held by udevd/5164: 2 locks held by getty/5555: #0: ffff88823bfe60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by syz.7.645/10477: #0: ffff88803bc0c480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833 #2: ffff88805f66a8e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_create+0x22e/0xb10 fs/jfs/namei.c:101 #3: ffff88805f696368 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_create+0x249/0xb10 fs/jfs/namei.c:102 2 locks held by syz.7.645/10497: #0: ffff88803bc0c480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928 2 locks held by syz.7.645/10498: #0: ffff88803bc0c480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2929 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2940 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4928 2 locks held by syz.7.645/10499: #0: ffff88803bc0c480 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: open_last_lookups fs/namei.c:4586 [inline] #1: ffff88805f66acb8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4833 10 locks held by syz-executor/10974: 1 lock held by syz-executor/11795: 1 lock held by syz-executor/12592: #0: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f15d4b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 1 lock held by syz.9.895/12693: #0: ffff8880368c40d0 (&type->s_umount_key#71/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 3 locks held by syz.7.896/12699: 3 locks held by syz.4.898/12715: #0: ffff88801d7ffe60 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:461 [inline] #0: ffff88801d7ffe60 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x6a3/0x820 fs/fsopen.c:350 #1: ffff8880608e00d0 (&type->s_umount_key#41/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 #2: ffffffff8de70798 (bpf_preload_lock){+.+.}-{4:4}, at: populate_bpffs kernel/bpf/inode.c:972 [inline] #2: ffffffff8de70798 (bpf_preload_lock){+.+.}-{4:4}, at: bpf_fill_super+0x281/0xa60 kernel/bpf/inode.c:1019 1 lock held by dhcpcd-run-hook/12717: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 de fb 93 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ef 1f fa fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 5a 8c f7 05 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001679d0 EFLAGS: 00000202 RAX: 1ffffffff332bb00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff9995dd10 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff853085c0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9995da80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126332000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f42054f5d58 CR3: 0000000035c62000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1970 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline] serial8250_console_write+0x120d/0x1b90 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245