syzbot

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BUG: KCSAN: data-race in bq_flush_to_queue / cpu_map_kthread_run

write to 0xffff888117d45c80 of 8 bytes by task 15060 on cpu 0:
 __ptr_ring_discard_one include/linux/ptr_ring.h:280 [inline]
 __ptr_ring_consume include/linux/ptr_ring.h:301 [inline]
 __ptr_ring_consume_batched include/linux/ptr_ring.h:313 [inline]
 cpu_map_kthread_run+0x4a1/0x11e0 kernel/bpf/cpumap.c:307
 kthread+0x4ae/0x520 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888117d45c80 of 8 bytes by task 15059 on cpu 1:
 __ptr_ring_produce include/linux/ptr_ring.h:106 [inline]
 bq_flush_to_queue+0x125/0x360 kernel/bpf/cpumap.c:691
 bq_enqueue kernel/bpf/cpumap.c:715 [inline]
 cpu_map_enqueue+0x19e/0x1b0 kernel/bpf/cpumap.c:741
 __xdp_do_redirect_frame net/core/filter.c:4424 [inline]
 xdp_do_redirect_frame+0x2a4/0x6b0 net/core/filter.c:4475
 xdp_test_run_batch net/bpf/test_run.c:341 [inline]
 bpf_test_run_xdp_live+0x8c7/0x1040 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x51d/0x8b0 net/bpf/test_run.c:1319
 bpf_prog_test_run+0x20f/0x3a0 kernel/bpf/syscall.c:4406
 __sys_bpf+0x400/0x7a0 kernel/bpf/syscall.c:5812
 __do_sys_bpf kernel/bpf/syscall.c:5901 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5899 [inline]
 __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5899
 x64_sys_call+0x2914/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:322
 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: 0xffff8881197c4070 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 15059 Comm: syz.0.5032 Tainted: G        W          6.14.0-rc3-syzkaller-00096-ge9a8cac0bf89 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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