================================================================== BUG: KCSAN: data-race in copy_process / free_pid read-write to 0xffffffff86860008 of 4 bytes by task 15729 on cpu 0: free_pid+0xb9/0x1d0 kernel/pid.c:126 free_pids+0x7a/0xb0 kernel/pid.c:159 release_task+0x9a7/0xb60 kernel/exit.c:295 exit_notify kernel/exit.c:777 [inline] do_exit+0xd4d/0x1590 kernel/exit.c:983 call_usermodehelper_exec_async+0x247/0x250 kernel/umh.c:122 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 read to 0xffffffff86860008 of 4 bytes by task 9530 on cpu 1: copy_process+0x16d4/0x1ef0 kernel/fork.c:2394 kernel_clone+0x16c/0x5c0 kernel/fork.c:2651 user_mode_thread+0x7d/0xb0 kernel/fork.c:2727 call_usermodehelper_exec_work+0x41/0x160 kernel/umh.c:171 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340 worker_thread+0x582/0x770 kernel/workqueue.c:3421 kthread+0x489/0x510 kernel/kthread.c:463 ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 value changed: 0x80000136 -> 0x80000135 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 9530 Comm: kworker/u8:68 Tainted: G W syzkaller #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound call_usermodehelper_exec_work ================================================================== 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): Released all slaves bond1 (unregistering): Released all slaves bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves tipc: Disabling bearer tipc: Left network mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed IPVS: stop unused estimator thread 0... IPVS: stop unused estimator thread 0... netdevsim netdevsim1 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim6 netdevsim3 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim6 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim6 netdevsim2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim6 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim6 netdevsim1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim6 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim6 netdevsim0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim6 netdevsim0 (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 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 team0: Port device bridge0 removed bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (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 hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode 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 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 team0 (unregistering): Port device dummy0 removed team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed IPVS: stop unused estimator thread 0... netdevsim netdevsim3 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim3 netdevsim0 (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 bond1 (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