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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237c2a8a4 of 4 bytes by task 3368 on cpu 0:
 wq_worker_running+0x95/0x120 kernel/workqueue.c:1419
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:7061
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x502/0xed0 kernel/locking/mutex.c:776
 __mutex_lock_slowpath+0xa/0x10 kernel/locking/mutex.c:1065
 mutex_lock+0x88/0x90 kernel/locking/mutex.c:290
 pcpu_balance_workfn+0x49/0xa40 mm/percpu.c:2210
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358
 worker_thread+0x581/0x770 kernel/workqueue.c:3439
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c2a8a4 of 4 bytes by task 3318 on cpu 1:
 need_more_worker kernel/workqueue.c:937 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1259
 __queue_work+0x896/0xaf0 kernel/workqueue.c:2355
 queue_work_on+0xa9/0x140 kernel/workqueue.c:2405
 queue_work include/linux/workqueue.h:669 [inline]
 schedule_work include/linux/workqueue.h:730 [inline]
 pcpu_schedule_balance_work mm/percpu.c:204 [inline]
 pcpu_alloc_noprof+0x728/0x1030 mm/percpu.c:1862
 xt_percpu_counter_alloc+0x78/0x110 net/netfilter/x_tables.c:1934
 find_check_entry net/ipv4/netfilter/ip_tables.c:526 [inline]
 translate_table+0x94c/0x10d0 net/ipv4/netfilter/ip_tables.c:716
 ipt_register_table+0x92/0x420 net/ipv4/netfilter/ip_tables.c:1742
 iptable_mangle_table_init+0x4d/0x70 net/ipv4/netfilter/iptable_mangle.c:92
 xt_find_table_lock+0x1a7/0x2c0 net/netfilter/x_tables.c:1260
 xt_request_find_table_lock+0x24/0xa0 net/netfilter/x_tables.c:1285
 get_info net/ipv4/netfilter/ip_tables.c:963 [inline]
 do_ipt_get_ctl+0x590/0xc00 net/ipv4/netfilter/ip_tables.c:1659
 nf_getsockopt+0x190/0x1b0 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x137/0x180 net/ipv4/ip_sockglue.c:1777
 tcp_getsockopt+0xad/0xe0 net/ipv4/tcp.c:4893
 sock_common_getsockopt+0x60/0x70 net/core/sock.c:3946
 do_sock_getsockopt+0x1c4/0x210 net/socket.c:2383
 __sys_getsockopt net/socket.c:2412 [inline]
 __do_sys_getsockopt net/socket.c:2419 [inline]
 __se_sys_getsockopt net/socket.c:2416 [inline]
 __x64_sys_getsockopt+0x11d/0x1a0 net/socket.c:2416
 x64_sys_call+0x2dcf/0x3020 arch/x86/include/generated/asm/syscalls_64.h:56
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3318 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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