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BUG: KCSAN: data-race in pcpu_alloc / pcpu_block_update_hint_alloc

read-write to 0xffffffff883d54dc of 4 bytes by task 3114 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+0x49f/0x4d0 mm/percpu.c:1258
 pcpu_alloc+0x4b3/0x10d0 mm/percpu.c:1808
 __alloc_percpu+0x24/0x30 mm/percpu.c:1943
 xt_percpu_counter_alloc+0x72/0x110 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:1743
 ip6table_mangle_table_init+0x4e/0x70 net/ipv6/netfilter/ip6table_mangle.c:85
 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:1660
 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:4373
 sock_common_getsockopt+0x5b/0x70 net/core/sock.c:3700
 do_sock_getsockopt+0x121/0x1a0 net/socket.c:2373
 __sys_getsockopt+0x19a/0x210 net/socket.c:2402
 __do_sys_getsockopt net/socket.c:2412 [inline]
 __se_sys_getsockopt net/socket.c:2409 [inline]
 __x64_sys_getsockopt+0x66/0x80 net/socket.c:2409
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffffffff883d54dc of 4 bytes by task 3252 on cpu 1:
 pcpu_alloc+0x9aa/0x10d0 mm/percpu.c:1868
 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930
 __percpu_counter_init_many+0x3c/0x1f0 lib/percpu_counter.c:164
 io_uring_alloc_task_context+0x7b/0x2d0 io_uring/tctx.c:70
 __io_uring_add_tctx_node+0x1e0/0x2b0 io_uring/tctx.c:101
 io_uring_create+0x81b/0x940 io_uring/io_uring.c:4002
 io_uring_setup io_uring/io_uring.c:4056 [inline]
 __do_sys_io_uring_setup io_uring/io_uring.c:4083 [inline]
 __se_sys_io_uring_setup+0x1d2/0x1e0 io_uring/io_uring.c:4077
 __x64_sys_io_uring_setup+0x31/0x40 io_uring/io_uring.c:4077
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x00000002 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3252 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-11752-gdba89d1b81df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
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