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BUG: KCSAN: data-race in pcpu_alloc / pcpu_alloc

read-write to 0xffffffff86f41634 of 4 bytes by task 6387 on cpu 0:
 pcpu_reintegrate_chunk mm/percpu.c:584 [inline]
 pcpu_alloc+0x7e7/0x1280 mm/percpu.c:1812
 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930
 bpf_map_alloc_percpu+0xaa/0x200 kernel/bpf/syscall.c:491
 prealloc_init kernel/bpf/hashtab.c:322 [inline]
 htab_map_alloc+0x8a1/0xde0 kernel/bpf/hashtab.c:555
 find_and_alloc_map kernel/bpf/syscall.c:131 [inline]
 map_create+0x398/0x710 kernel/bpf/syscall.c:1138
 __sys_bpf+0x60c/0x810 kernel/bpf/syscall.c:4974
 __do_sys_bpf kernel/bpf/syscall.c:5096 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5094 [inline]
 __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094
 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

read to 0xffffffff86f41634 of 4 bytes by task 6373 on cpu 1:
 pcpu_alloc+0xa59/0x1280 mm/percpu.c:1870
 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930
 qdisc_alloc+0x18b/0x430 net/sched/sch_generic.c:949
 qdisc_create_dflt+0x4c/0x270 net/sched/sch_generic.c:996
 mq_init+0x1bf/0x390 net/sched/sch_mq.c:90
 qdisc_create_dflt+0xcd/0x270 net/sched/sch_generic.c:1003
 attach_default_qdiscs net/sched/sch_generic.c:1174 [inline]
 dev_activate+0xdc/0x970 net/sched/sch_generic.c:1228
 __dev_open+0x2eb/0x3a0 net/core/dev.c:1426
 __dev_change_flags+0x159/0x400 net/core/dev.c:8527
 dev_change_flags+0x59/0xd0 net/core/dev.c:8599
 dev_ifsioc+0x42d/0xaf0 net/core/dev_ioctl.c:327
 dev_ioctl+0x7e9/0xa90 net/core/dev_ioctl.c:588
 sock_do_ioctl+0x116/0x250 net/socket.c:1213
 sock_ioctl+0x469/0x630 net/socket.c:1316
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 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: 0x00000003 -> 0xfffffffb

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 6373 Comm: syz-executor.0 Not tainted 6.3.0-rc5-syzkaller-00137-gf2afccfefe7b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
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