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BUG: KCSAN: data-race in pcpu_alloc_noprof / pcpu_block_update_hint_alloc

read-write to 0xffffffff8841e6ac of 4 bytes by task 3099 on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:602 [inline]
 pcpu_block_update_hint_alloc+0x5db/0x6a0 mm/percpu.c:923
 pcpu_alloc_area+0x488/0x4b0 mm/percpu.c:1258
 pcpu_alloc_noprof+0x4b3/0x10c0 mm/percpu.c:1834
 xt_percpu_counter_alloc+0x79/0x110 net/netfilter/x_tables.c:1931
 find_check_entry net/ipv6/netfilter/ip6_tables.c:545 [inline]
 translate_table+0x9b1/0x1040 net/ipv6/netfilter/ip6_tables.c:733
 ip6t_register_table+0x9a/0x440 net/ipv6/netfilter/ip6_tables.c:1751
 ip6table_nat_table_init+0x42/0x280 net/ipv6/netfilter/ip6table_nat.c:116
 xt_find_table_lock+0x194/0x260 net/netfilter/x_tables.c:1260
 xt_request_find_table_lock+0x26/0xa0 net/netfilter/x_tables.c:1285
 get_info net/ipv6/netfilter/ip6_tables.c:979 [inline]
 do_ip6t_get_ctl+0x554/0xc00 net/ipv6/netfilter/ip6_tables.c:1668
 nf_getsockopt+0x18c/0x1b0 net/netfilter/nf_sockopt.c:116
 ipv6_getsockopt+0x189/0x1f0 net/ipv6/ipv6_sockglue.c:1494
 tcp_getsockopt+0xaa/0xe0 net/ipv4/tcp.c:4399
 sock_common_getsockopt+0x5b/0x70 net/core/sock.c:3699
 do_sock_getsockopt+0x121/0x1a0 net/socket.c:2374
 __sys_getsockopt+0x19a/0x210 net/socket.c:2403
 __do_sys_getsockopt net/socket.c:2413 [inline]
 __se_sys_getsockopt net/socket.c:2410 [inline]
 __x64_sys_getsockopt+0x66/0x80 net/socket.c:2410
 x64_sys_call+0x2d21/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:56
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff8841e6ac of 4 bytes by task 3109 on cpu 1:
 pcpu_alloc_noprof+0x9a7/0x10c0 mm/percpu.c:1894
 fib_nh_common_init+0x4a/0x2b0 net/ipv4/fib_semantics.c:591
 fib6_nh_init+0xf33/0x15d0 net/ipv6/route.c:3620
 ip6_route_info_create+0x7b7/0xba0 net/ipv6/route.c:3807
 addrconf_f6i_alloc+0x188/0x280 net/ipv6/route.c:4586
 ipv6_add_addr+0x3c8/0x820 net/ipv6/addrconf.c:1120
 inet6_addr_add+0x3ff/0x660 net/ipv6/addrconf.c:3059
 inet6_rtm_newaddr+0x4c4/0x590 net/ipv6/addrconf.c:5047
 rtnetlink_rcv_msg+0x82e/0x8e0 net/core/rtnetlink.c:6595
 netlink_rcv_skb+0x12c/0x230 net/netlink/af_netlink.c:2564
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6613
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x58d/0x660 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x5ca/0x6e0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:745
 __sys_sendto+0x1e5/0x260 net/socket.c:2192
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0x78/0x90 net/socket.c:2200
 x64_sys_call+0x16d7/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3109 Comm: syz-executor.3 Not tainted 6.10.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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