==================================================================
BUG: KCSAN: data-race in free_kthread_struct / kthread_is_per_cpu

write to 0xffff88813867f128 of 8 bytes by task 1975 on cpu 1:
 free_kthread_struct+0x6f/0xb0 kernel/kthread.c:143
 begin_new_exec+0xc3a/0x1060 fs/exec.c:1312
 load_elf_binary+0x62a/0x1970 fs/binfmt_elf.c:1002
 search_binary_handler fs/exec.c:1726 [inline]
 exec_binprm+0x1d9/0x800 fs/exec.c:1767
 bprm_execve+0x379/0x4e0 fs/exec.c:1836
 kernel_execve+0x62b/0x660 fs/exec.c:1997
 call_usermodehelper_exec_async+0x1a6/0x250 kernel/umh.c:112
 ret_from_fork+0x1f/0x30

read to 0xffff88813867f128 of 8 bytes by task 1839 on cpu 0:
 __to_kthread kernel/kthread.c:92 [inline]
 kthread_is_per_cpu+0x18/0x80 kernel/kthread.c:606
 can_migrate_task+0x13/0x1b0 kernel/sched/fair.c:7807
 detach_tasks+0xab/0x380 kernel/sched/fair.c:7971
 load_balance+0x7c3/0xcd0 kernel/sched/fair.c:9960
 newidle_balance+0x168/0x340 kernel/sched/fair.c:10969
 pick_next_task_fair+0x37/0x260 kernel/sched/fair.c:7387
 __pick_next_task kernel/sched/core.c:5695 [inline]
 pick_next_task kernel/sched/core.c:6204 [inline]
 __schedule+0x270/0x6c0 kernel/sched/core.c:6352
 schedule+0x71/0xa0 kernel/sched/core.c:6460
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6519
 __mutex_lock_common kernel/locking/mutex.c:673 [inline]
 __mutex_lock+0x36c/0x5b0 kernel/locking/mutex.c:733
 __mutex_lock_slowpath+0xa/0x10 kernel/locking/mutex.c:1021
 mutex_lock+0x23/0x30 kernel/locking/mutex.c:283
 rtnl_lock net/core/rtnetlink.c:72 [inline]
 rtnetlink_rcv_msg+0x350/0x7e0 net/core/rtnetlink.c:5990
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6011
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x661/0x750 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 __sys_sendto+0x21e/0x2c0 net/socket.c:2040
 __do_sys_sendto net/socket.c:2052 [inline]
 __se_sys_sendto net/socket.c:2048 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff8881387e0d00 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1839 Comm: syz-executor.1 Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
device veth0_vlan entered promiscuous mode
device veth1_vlan entered promiscuous mode
device veth0_macvtap entered promiscuous mode
device veth1_macvtap entered promiscuous mode
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: batadv0: Interface activated: batadv_slave_0
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: batadv0: Interface activated: batadv_slave_1
netdevsim netdevsim1 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0