================================================================== BUG: KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn read-write to 0xffffffff86eeb29c of 4 bytes by task 2743 on cpu 1: pcpu_update_empty_pages mm/percpu.c:602 [inline] pcpu_chunk_populated mm/percpu.c:1531 [inline] pcpu_balance_populated mm/percpu.c:2090 [inline] pcpu_balance_workfn+0x96f/0xa80 mm/percpu.c:2240 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read to 0xffffffff86eeb29c of 4 bytes by task 3087 on cpu 0: pcpu_alloc+0xa59/0x12a0 mm/percpu.c:1870 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1932 ipip6_tunnel_init+0x82/0x240 net/ipv6/sit.c:1452 register_netdevice+0x213/0xb20 net/core/dev.c:10067 register_netdev+0x3b/0x50 net/core/dev.c:10266 sit_init_net+0x1c0/0x370 net/ipv6/sit.c:1860 ops_init+0x1fc/0x2c0 net/core/net_namespace.c:136 setup_net+0x2cd/0x710 net/core/net_namespace.c:339 copy_net_ns+0x384/0x520 net/core/net_namespace.c:491 create_new_namespaces+0x228/0x430 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xe4/0x120 kernel/nsproxy.c:228 ksys_unshare+0x38d/0x6d0 kernel/fork.c:3435 __do_sys_unshare kernel/fork.c:3506 [inline] __se_sys_unshare kernel/fork.c:3504 [inline] __x64_sys_unshare+0x1f/0x30 kernel/fork.c:3504 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000001 -> 0x00000004 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 3087 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-00038-g0e945134b680 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 ================================================================== chnl_net:caif_netlink_parms(): no params data found bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state bridge_slave_0: entered allmulticast mode bridge_slave_0: entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_1: entered allmulticast mode bridge_slave_1: entered promiscuous mode bond0: (slave bond_slave_0): Enslaving as an active interface with an up link bond0: (slave bond_slave_1): Enslaving as an active interface with an up link team0: Port device team_slave_0 added team0: Port device team_slave_1 added batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active hsr_slave_0: entered promiscuous mode hsr_slave_1: entered promiscuous mode debugfs: Directory 'hsr0' with parent 'hsr' already present! Cannot create hsr debugfs directory netdevsim netdevsim0 netdevsim0: renamed from eth0 netdevsim netdevsim0 netdevsim1: renamed from eth1 netdevsim netdevsim0 netdevsim2: renamed from eth2 netdevsim netdevsim0 netdevsim3: renamed from eth3 8021q: adding VLAN 0 to HW filter on device bond0 8021q: adding VLAN 0 to HW filter on device team0 hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network 8021q: adding VLAN 0 to HW filter on device batadv0 veth0_vlan: entered promiscuous mode veth1_vlan: entered promiscuous mode veth0_macvtap: entered promiscuous mode veth1_macvtap: entered promiscuous mode batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) 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:3e) 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:3e) 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:3f) 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:3f) 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:3f) 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:3f) 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 netdevsim0 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0