INFO: task syz.1.676:7759 blocked for more than 143 seconds.
Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.676 state:D stack:27136 pid:7759 tgid:7758 ppid:5230 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5322 [inline]
__schedule+0x1895/0x4b30 kernel/sched/core.c:6682
__schedule_loop kernel/sched/core.c:6759 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
rtnl_lock net/core/rtnetlink.c:79 [inline]
rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551
netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:729 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:744
____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
___sys_sendmsg net/socket.c:2661 [inline]
__sys_sendmsg+0x292/0x380 net/socket.c:2690
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: 0033:0x7f45e8d7e719
RSP: 002b:00007f45e9adb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f45e8f35f80 RCX: 00007f45e8d7e719
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00007f45e8df132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f45e8f35f80 R15: 00007ffe9d13eda8
INFO: task syz-executor:7761 blocked for more than 144 seconds.
Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:24128 pid:7761 tgid:7761 ppid:1 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5322 [inline]
__schedule+0x1895/0x4b30 kernel/sched/core.c:6682
__schedule_loop kernel/sched/core.c:6759 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6774
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
rtnl_lock net/core/rtnetlink.c:79 [inline]
rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2551
netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357
netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:729 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:744
__sys_sendto+0x39b/0x4f0 net/socket.c:2214
__do_sys_sendto net/socket.c:2226 [inline]
__se_sys_sendto net/socket.c:2222 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2222
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: 0033:0x7fbabb1805ac
RSP: 002b:00007fff24369120 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fbabbe64620 RCX: 00007fbabb1805ac
RDX: 0000000000000028 RSI: 00007fbabbe64670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007fff24369174 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fbabbe64670 R15: 0000000000000000
Showing all locks held in the system:
5 locks held by kworker/0:1/9:
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
2 locks held by getty/4988:
#0: ffff8880327420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:6/5286:
#0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc90004187d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc90004187d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x99/0xfd0 net/wireless/reg.c:2480
3 locks held by kworker/u8:17/5755:
#0: ffff8881456e2148 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff8881456e2148 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc9000df8fd00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc9000df8fd00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: cfg80211_dfs_channels_update_work+0xbf/0x610 net/wireless/mlme.c:1021
3 locks held by kworker/u8:23/5761:
#0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc9000decfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc9000decfd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
3 locks held by kworker/u8:30/5769:
#0: ffff88802df7b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88802df7b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc9000e26fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc9000e26fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4736
6 locks held by kworker/u8:31/5770:
#0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc9000e27fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc9000e27fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
#2: ffffffff8fcc6450 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:587
#3: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1662
#4: ffff888029260768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:6014 [inline]
#4: ffff888029260768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: ieee80211_remove_interfaces+0x12b/0x700 net/mac80211/iface.c:2275
#5: ffffffff8e7d1dd0 (cpu_hotplug_lock){++++}-{0:0}, at: flush_all_backlogs net/core/dev.c:6027 [inline]
#5: ffffffff8e7d1dd0 (cpu_hotplug_lock){++++}-{0:0}, at: unregister_netdevice_many_notify+0x5ea/0x1da0 net/core/dev.c:11458
2 locks held by syz.4.655/7660:
#0: ffffffff8fcc6450 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:497
#1: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: mpls_net_exit+0x7d/0x2a0 net/mpls/af_mpls.c:2706
2 locks held by syz-executor/7673:
#0: ffffffff8fcc6450 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:497
#1: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414
1 lock held by syz.1.676/7759:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7761:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz.2.678/7764:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz.2.678/7769:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x706/0x1340 net/core/dev_ioctl.c:782
1 lock held by syz.2.678/7775:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
2 locks held by syz.3.681/7774:
#0: ffffffff8fd39430 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5f/0x8b0 net/wireless/nl80211.c:16580
1 lock held by syz-executor/7784:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7788:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7790:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7793:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7796:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7799:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7803:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7805:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7813:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7816:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
1 lock held by syz-executor/7819:
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fcd2fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6746
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #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+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x6a7/0x22d0 arch/x86/kernel/unwind_orc.c:494
Code: 4c 89 7c 24 28 48 8b 44 24 58 42 80 3c 20 00 74 08 4c 89 f7 e8 0a 2b bd 00 49 8b 2e e9 32 02 00 00 4d 89 ec 4d 89 ee 48 89 e8 <4c> 29 f0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49
RSP: 0018:ffffc90000007310 EFLAGS: 00000202
RAX: ffffffff90357994 RBX: ffffffff914f7e24 RCX: ffffffff90aeca12
RDX: 00000000000b0001 RSI: ffffffff90aec9dc RDI: 0000000000000001
RBP: ffffffff90357994 R08: 0000000000000009 R09: ffffc900000074d0
R10: ffffc90000007430 R11: ffffffff8180a0e0 R12: ffffffff90357974
R13: ffffffff90357974 R14: ffffffff90357974 R15: ffffffff81f28c34
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f28652cdd58 CR3: 000000000e734000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4085 [inline]
slab_alloc_node mm/slub.c:4134 [inline]
kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
skb_clone+0x20c/0x390 net/core/skbuff.c:2084
can_can_gw_rcv+0x3ce/0x1070 net/can/gw.c:512
deliver net/can/af_can.c:572 [inline]
can_rcv_filter+0x11c/0x7f0 net/can/af_can.c:599
can_receive+0x327/0x480 net/can/af_can.c:663
can_rcv+0x144/0x260 net/can/af_can.c:687
__netif_receive_skb_one_core net/core/dev.c:5668 [inline]
__netif_receive_skb+0x2e0/0x650 net/core/dev.c:5781
process_backlog+0x662/0x15b0 net/core/dev.c:6113
__napi_poll+0xcb/0x490 net/core/dev.c:6834
napi_poll net/core/dev.c:6903 [inline]
net_rx_action+0x89b/0x1240 net/core/dev.c:7025
handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
do_softirq+0x11b/0x1e0 kernel/softirq.c:455
__local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
spin_unlock_bh include/linux/spinlock.h:396 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244