================================================================== BUG: KCSAN: data-race in copy_process / free_pid read-write to 0xffffffff8685f030 of 4 bytes by task 8765 on cpu 0: free_pid+0x77/0x180 kernel/pid.c:125 free_pids+0x9e/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 do_group_exit+0xff/0x140 kernel/exit.c:1102 get_signal+0xe59/0xf70 kernel/signal.c:3034 arch_do_signal_or_restart+0x97/0x480 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x68/0xb0 kernel/entry/common.c:218 do_syscall_64+0xdd/0x1a0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff8685f030 of 4 bytes by task 263 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_sync kernel/umh.c:132 [inline] call_usermodehelper_exec_work+0x7a/0x160 kernel/umh.c:163 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319 worker_thread+0x582/0x770 kernel/workqueue.c:3400 kthread+0x486/0x510 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: 0x800000bc -> 0x800000bb Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 263 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #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 netdevsim4 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim4 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim4 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim4 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim7 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim7 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim7 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim7 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: left allmulticast mode bond_slave_0: left allmulticast mode bond_slave_1: left allmulticast mode bond0: left promiscuous mode bond_slave_0: left promiscuous mode bond_slave_1: left promiscuous mode bridge0: port 3(bond0) 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): 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 bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves tipc: Left network mode tipc: Disabling bearer tipc: Left network mode IPVS: stopping master sync thread 4324 ... IPVS: stopping backup sync thread 6889 ... hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 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_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 batadv_slave_0: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 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 team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed pimreg (unregistering): left allmulticast mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed IPVS: stop unused estimator thread 0...