================================================================== BUG: KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn read-write to 0xffffffff86f595d4 of 4 bytes by task 2731 on cpu 0: pcpu_update_empty_pages mm/percpu.c:602 [inline] pcpu_chunk_populated mm/percpu.c:1531 [inline] pcpu_balance_populated mm/percpu.c:2088 [inline] pcpu_balance_workfn+0x96f/0xa80 mm/percpu.c:2238 process_one_work+0x3e6/0x750 kernel/workqueue.c:2405 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 read to 0xffffffff86f595d4 of 4 bytes by task 3088 on cpu 1: pcpu_alloc+0xa59/0x1280 mm/percpu.c:1870 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930 fib_nh_common_init+0x48/0x2b0 net/ipv4/fib_semantics.c:590 fib_nh_init+0x64/0x1a0 net/ipv4/fib_semantics.c:629 fib_create_info+0xa22/0x1500 net/ipv4/fib_semantics.c:1492 fib_table_insert+0x101/0xf70 net/ipv4/fib_trie.c:1236 fib_magic+0x1a1/0x1f0 net/ipv4/fib_frontend.c:1104 fib_add_ifaddr+0x281/0x320 net/ipv4/fib_frontend.c:1141 fib_netdev_event+0x357/0x430 net/ipv4/fib_frontend.c:1486 notifier_call_chain kernel/notifier.c:93 [inline] raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461 __dev_notify_flags+0x205/0x3d0 dev_change_flags+0xab/0xd0 net/core/dev.c:8645 do_setlink+0x9ad/0x23a0 net/core/rtnetlink.c:2867 __rtnl_newlink net/core/rtnetlink.c:3648 [inline] rtnl_newlink+0x10cb/0x15a0 net/core/rtnetlink.c:3695 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6417 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6435 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2144 __do_sys_sendto net/socket.c:2156 [inline] __se_sys_sendto net/socket.c:2152 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2152 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: 1 PID: 3088 Comm: syz-executor.5 Not tainted 6.4.0-rc5-syzkaller-00178-g33f2b5785a2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 ================================================================== 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: 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: 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 netdevsim5 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim5 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim5 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim5 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0