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BUG: KCSAN: data-race in pcpu_alloc / pcpu_block_update_hint_alloc

read-write to 0xffffffff884034dc of 4 bytes by task 15530 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
 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline]
 do_ip6t_set_ctl+0x7cc/0x8c0 net/ipv6/netfilter/ip6_tables.c:1644
 nf_setsockopt+0x195/0x1b0 net/netfilter/nf_sockopt.c:101
 ipv6_setsockopt+0x126/0x140 net/ipv6/ipv6_sockglue.c:999
 tcp_setsockopt+0x93/0xb0 net/ipv4/tcp.c:3737
 sock_common_setsockopt+0x64/0x80 net/core/sock.c:3727
 do_sock_setsockopt net/socket.c:2311 [inline]
 __sys_setsockopt+0x1d8/0x250 net/socket.c:2334
 __do_sys_setsockopt net/socket.c:2343 [inline]
 __se_sys_setsockopt net/socket.c:2340 [inline]
 __x64_sys_setsockopt+0x66/0x80 net/socket.c:2340
 x64_sys_call+0x1159/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:55
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff884034dc of 4 bytes by task 16574 on cpu 1:
 pcpu_alloc+0x9aa/0x10d0 mm/percpu.c:1868
 __alloc_percpu+0x24/0x30 mm/percpu.c:1943
 qdisc_alloc+0x281/0x430 net/sched/sch_generic.c:956
 qdisc_create_dflt+0x4c/0x280 net/sched/sch_generic.c:999
 mq_init+0x1b9/0x380 net/sched/sch_mq.c:90
 qdisc_create_dflt+0xce/0x280 net/sched/sch_generic.c:1006
 attach_default_qdiscs net/sched/sch_generic.c:1187 [inline]
 dev_activate+0xd9/0x9e0 net/sched/sch_generic.c:1241
 __dev_open+0x263/0x2e0 net/core/dev.c:1439
 __dev_change_flags+0x155/0x410 net/core/dev.c:8686
 dev_change_flags+0x59/0xd0 net/core/dev.c:8758
 dev_ifsioc+0x67f/0xa10 net/core/dev_ioctl.c:530
 dev_ioctl+0x7fa/0xab0 net/core/dev_ioctl.c:787
 sock_do_ioctl+0x11c/0x260 net/socket.c:1236
 sock_ioctl+0x470/0x640 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0xd3/0x150 fs/ioctl.c:890
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:890
 x64_sys_call+0x155d/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000046 -> 0x00000045

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16574 Comm: syz-executor.1 Not tainted 6.9.0-rc3-syzkaller-00208-g586b5dfb51b9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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syzkaller0: entered promiscuous mode
syzkaller0: entered allmulticast mode