syzbot

device veth0_vlan entered promiscuous mode
device veth1_vlan entered promiscuous mode
==================================================================
BUG: KCSAN: data-race in pcpu_alloc / pcpu_alloc

read-write to 0xffffffff870d6b74 of 4 bytes by task 1815 on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:606 [inline]
 pcpu_chunk_populated mm/percpu.c:1534 [inline]
 pcpu_alloc+0x8e8/0xf60 mm/percpu.c:1870
 __alloc_percpu+0x20/0x30 mm/percpu.c:1950
 xt_percpu_counter_alloc+0x6e/0x110 net/netfilter/x_tables.c:1930
 find_check_entry net/ipv6/netfilter/ip6_tables.c:547 [inline]
 translate_table+0x9ff/0x1090 net/ipv6/netfilter/ip6_tables.c:735
 ip6t_register_table+0x95/0x3d0 net/ipv6/netfilter/ip6_tables.c:1746
 ip6table_filter_table_init+0x84/0xb0 net/ipv6/netfilter/ip6table_filter.c:48
 xt_find_table_lock+0x1c9/0x2d0 net/netfilter/x_tables.c:1259
 xt_request_find_table_lock+0x22/0xa0 net/netfilter/x_tables.c:1284
 get_info net/ipv6/netfilter/ip6_tables.c:981 [inline]
 do_ip6t_get_ctl+0x53a/0xbe0 net/ipv6/netfilter/ip6_tables.c:1663
 nf_getsockopt+0x18f/0x1b0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x191/0x1f0 net/ipv6/ipv6_sockglue.c:1513
 tcp_getsockopt+0xa3/0xd0 net/ipv4/tcp.c:4402
 sock_common_getsockopt+0x53/0x60 net/core/sock.c:3614
 __sys_getsockopt+0x17a/0x1e0 net/socket.c:2296
 __do_sys_getsockopt net/socket.c:2311 [inline]
 __se_sys_getsockopt net/socket.c:2308 [inline]
 __x64_sys_getsockopt+0x62/0x70 net/socket.c:2308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffffffff870d6b74 of 4 bytes by task 1829 on cpu 1:
 pcpu_alloc+0x91d/0xf60 mm/percpu.c:1877
 __alloc_percpu_gfp+0x22/0x30 mm/percpu.c:1937
 fib6_nh_init+0x602/0x1370 net/ipv6/route.c:3614
 ip6_route_info_create+0x7ca/0xbb0 net/ipv6/route.c:3799
 addrconf_f6i_alloc+0x16c/0x260 net/ipv6/route.c:4571
 fixup_permanent_addr net/ipv6/addrconf.c:3461 [inline]
 addrconf_permanent_addr+0x13d/0x5d0 net/ipv6/addrconf.c:3500
 addrconf_notify+0x626/0x960 net/ipv6/addrconf.c:3572
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:455
 __dev_notify_flags+0x1d6/0x3a0
 dev_change_flags+0xa2/0xc0 net/core/dev.c:8619
 do_setlink+0x9a5/0x2210 net/core/rtnetlink.c:2788
 __rtnl_newlink net/core/rtnetlink.c:3547 [inline]
 rtnl_newlink+0x114c/0x16a0 net/core/rtnetlink.c:3594
 rtnetlink_rcv_msg+0x811/0x8d0 net/core/rtnetlink.c:6091
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2540
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6109
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x666/0x760 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 __sys_sendto+0x22d/0x2d0 net/socket.c:2117
 __do_sys_sendto net/socket.c:2129 [inline]
 __se_sys_sendto net/socket.c:2125 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2125
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffffffff -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1829 Comm: syz-executor.2 Tainted: G        W          6.1.0-rc2-syzkaller-00351-g91562cf99364-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
==================================================================
device veth0_macvtap entered promiscuous mode
device 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 netdevsim2 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0