INFO: task udevd:9067 blocked for more than 144 seconds. Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:19216 pid:9067 tgid:9067 ppid:4682 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 bdev_open+0xf0/0xc50 block/bdev.c:904 blkdev_open+0x3d9/0x560 block/fops.c:631 do_dentry_open+0x97a/0x1460 fs/open.c:958 vfs_open+0x3e/0x330 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3933 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f63e99169a4 RSP: 002b:00007ffde8c25d30 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055f964c10e10 RCX: 00007f63e99169a4 RDX: 00000000000a0800 RSI: 000055f964c229b0 RDI: 00000000ffffff9c RBP: 000055f964c229b0 R08: 0000000000000001 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 000055f964c016f0 R14: 0000000000000001 R15: 000055f964bef910 INFO: task syz.4.571:9994 blocked for more than 145 seconds. Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.571 state:D stack:23808 pid:9994 tgid:9994 ppid:8895 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 bdev_release+0x17e/0x700 block/bdev.c:1087 blkdev_release+0x15/0x20 block/fops.c:639 __fput+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2997b7dff9 RSP: 002b:00007ffd1c5c2798 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f2997d37a80 RCX: 00007f2997b7dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f2997d37a80 R08: 0000000000000006 R09: 00007ffd1c5c2a8f R10: 00000000005eee20 R11: 0000000000000246 R12: 00000000000e6cd1 R13: 00007ffd1c5c28a0 R14: 0000000000000032 R15: ffffffffffffffff INFO: task syz.4.571:9995 blocked for more than 145 seconds. Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.571 state:D stack:23512 pid:9995 tgid:9994 ppid:8895 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 bdev_release+0x17e/0x700 block/bdev.c:1087 blkdev_release+0x15/0x20 block/fops.c:639 __fput+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2997b7dff9 RSP: 002b:00007f29988b2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f2997d35f80 RCX: 00007f2997b7dff9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004 RBP: 00007f2997bf0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2997d35f80 R15: 00007ffd1c5c2638 INFO: task syz.4.571:9996 blocked for more than 146 seconds. Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.571 state:D stack:21312 pid:9996 tgid:9994 ppid:8895 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 io_schedule+0x8d/0x110 kernel/sched/core.c:7552 folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1309 folio_put_wait_locked mm/filemap.c:1473 [inline] do_read_cache_folio+0xc8/0x850 mm/filemap.c:3807 read_mapping_folio include/linux/pagemap.h:1011 [inline] read_part_sector+0xb3/0x330 block/partitions/core.c:714 adfspart_check_POWERTEC+0xc8/0x8f0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:581 [inline] bdev_disk_changed+0x72e/0x13f0 block/partitions/core.c:685 blkdev_get_whole+0x2d2/0x450 block/bdev.c:707 bdev_open+0x2d4/0xc50 block/bdev.c:916 blkdev_open+0x3d9/0x560 block/fops.c:631 do_dentry_open+0x97a/0x1460 fs/open.c:958 vfs_open+0x3e/0x330 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x2c84/0x3590 fs/namei.c:3933 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2997b7c990 RSP: 002b:00007f2998890b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2997b7c990 RDX: 0000000000000000 RSI: 00007f2998890c10 RDI: 00000000ffffff9c RBP: 00007f2998890c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2997d36058 R15: 00007ffd1c5c2638 Showing all locks held in the system: 2 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 5 locks held by kworker/u8:2/35: #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc51d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616 #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:5/81: #0: ffff88814b951148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814b951148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900024bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900024bfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 3 locks held by kworker/u8:11/2995: #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000a317d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000a317d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by dhcpcd/4896: #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1097 2 locks held by getty/4983: #0: ffff88802e82a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:8/5313: #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900034ffd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900034ffd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by udevd/9067: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 3 locks held by kworker/u8:0/9754: 1 lock held by syz.4.571/9994: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x17e/0x700 block/bdev.c:1087 1 lock held by syz.4.571/9995: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x17e/0x700 block/bdev.c:1087 1 lock held by syz.4.571/9996: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by syz.4.602/10278: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by syz.4.602/10280: #0: ffff8880253174c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by syz-executor/10840: #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 7 locks held by syz-executor/10920: #0: ffff88807ca3a420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff88807ca3a420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88807acb8488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8881443ce698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f56fda8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88802f8b20e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88802f8b20e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88802f8b20e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88802f8b7250 (&devlink->lock_key#58){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 4 locks held by syz-executor/10974: #0: ffff88807ca3a420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #0: ffff88807ca3a420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff888031637088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8881443ce698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f56fda8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 1 lock held by syz-executor/10997: #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz.2.758/11188: #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1097 1 lock held by syz.1.762/11195: #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcd1cc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9754 Comm: kworker/u8:0 Not tainted 6.12.0-rc1-syzkaller-00349-g8f602276d390 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:arch_stack_walk+0x123/0x150 arch/x86/kernel/stacktrace.c:24 Code: c3 92 09 00 48 85 c0 74 23 4c 89 f7 48 89 c6 4d 89 eb e8 50 98 97 0a 84 c0 74 11 48 89 df e8 f4 93 09 00 83 bd 70 ff ff ff 00 <75> d0 65 48 8b 04 25 28 00 00 00 48 3b 45 d0 75 13 48 83 c4 68 5b RSP: 0018:ffffc9000353e900 EFLAGS: 00000202 RAX: 0000000080000201 RBX: ffffc9000353e900 RCX: 0000000080000201 RDX: dffffc0000000000 RSI: ffffc90003538000 RDI: 0000000000000001 RBP: ffffc9000353e990 R08: ffffc9000353eca8 R09: ffffc9000353e950 R10: dffffc0000000000 R11: fffff520006a7d2c R12: ffff88807d8ada00 R13: ffffffff81809000 R14: ffffc9000353e9e0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffddf05bfa8 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541 kvfree_call_rcu+0xfc/0x790 kernel/rcu/tree.c:3810 cfg80211_update_known_bss+0xb45/0x1590 net/wireless/scan.c:1891 __cfg80211_bss_update+0x153/0x2030 net/wireless/scan.c:1938 cfg80211_inform_single_bss_data+0xd82/0x2090 net/wireless/scan.c:2329 cfg80211_inform_bss_data+0x3ce/0x5e70 net/wireless/scan.c:3184 cfg80211_inform_bss_frame_data+0x3b8/0x720 net/wireless/scan.c:3279 ieee80211_bss_info_update+0x8a7/0xbc0 net/mac80211/scan.c:226 ieee80211_rx_bss_info net/mac80211/ibss.c:1100 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1579 [inline] ieee80211_ibss_rx_queued_mgmt+0x1962/0x2d70 net/mac80211/ibss.c:1606 ieee80211_iface_process_skb net/mac80211/iface.c:1603 [inline] ieee80211_iface_work+0x8a5/0xf20 net/mac80211/iface.c:1657 cfg80211_wiphy_work+0x2dd/0x490 net/wireless/core.c:440 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244