==================================================================
BUG: KCSAN: data-race in copy_process / free_pid

read-write to 0xffffffff8685f0b0 of 4 bytes by task 22074 on cpu 0:
 free_pid+0x77/0x180 kernel/pid.c:125
 free_pids+0x7a/0xb0 kernel/pid.c:158
 release_task+0x9d0/0xbb0 kernel/exit.c:289
 exit_notify kernel/exit.c:790 [inline]
 do_exit+0xee3/0x17c0 kernel/exit.c:973
 call_usermodehelper_exec_async+0x247/0x250 kernel/umh.c:122
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff8685f0b0 of 4 bytes by task 16957 on cpu 1:
 copy_process+0x1790/0x1f90 kernel/fork.c:2587
 kernel_clone+0x16c/0x5b0 kernel/fork.c:2844
 user_mode_thread+0x7d/0xb0 kernel/fork.c:2922
 call_usermodehelper_exec_work+0x41/0x160 kernel/umh.c:171
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x80000130 -> 0x8000012f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 16957 Comm: kworker/u8:12 Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: events_unbound call_usermodehelper_exec_work
==================================================================
netdevsim netdevsim0 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
bond0 (unregistering): Released all slaves
bond1 (unregistering): Released all slaves
bond2 (unregistering): Released all slaves
bond3 (unregistering): Released all slaves
bond4 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
netdevsim netdevsim8 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
netdevsim netdevsim9 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim9 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
team0: left allmulticast mode
team_slave_0: left allmulticast mode
team_slave_1: left allmulticast mode
bridge0: port 3(team0) entered disabled state
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
$Hÿ (unregistering): (slave bond_slave_0): Releasing backup interface
bond_slave_0: left promiscuous mode
$Hÿ (unregistering): (slave bond_slave_1): Releasing backup interface
bond_slave_1: left promiscuous mode
$Hÿ (unregistering): Released all slaves
bond1 (unregistering): Released all slaves
bond0 (unregistering): Released all slaves
bond2 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
team_slave_1 (unregistering): left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team_slave_0 (unregistering): left promiscuous mode
team0 (unregistering): Port device team_slave_0 removed