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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237d29de4 of 4 bytes by task 9771 on cpu 1:
 wq_worker_running+0x95/0x120 kernel/workqueue.c:1406
 schedule_timeout+0xb7/0x170 kernel/time/sleep_timeout.c:99
 schedule_timeout_uninterruptible kernel/time/sleep_timeout.c:158 [inline]
 msleep+0x50/0x90 kernel/time/sleep_timeout.c:318
 nsim_fib4_rt_add drivers/net/netdevsim/fib.c:369 [inline]
 nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:432 [inline]
 nsim_fib4_event drivers/net/netdevsim/fib.c:464 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:884 [inline]
 nsim_fib_event_work+0x3b21/0x4790 drivers/net/netdevsim/fib.c:1493
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237d29de4 of 4 bytes by task 11354 on cpu 0:
 need_more_worker kernel/workqueue.c:940 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1246
 __queue_work+0x8cb/0xb50 kernel/workqueue.c:2342
 queue_work_on+0xd1/0x160 kernel/workqueue.c:2392
 flush_all_rcu_sheaves+0xeb/0x170 mm/slub.c:4136
 kvfree_rcu_barrier+0x13/0x160 mm/slab_common.c:2059
 kmem_cache_destroy+0x17/0x130 mm/slab_common.c:495
 p9_client_destroy+0x1e6/0x220 net/9p/client.c:1088
 v9fs_session_close+0x35/0x110 fs/9p/v9fs.c:505
 v9fs_kill_super+0x3f/0x70 fs/9p/vfs_super.c:198
 deactivate_locked_super+0x75/0x1c0 fs/super.c:473
 v9fs_mount+0x520/0x5c0 fs/9p/vfs_super.c:179
 legacy_get_tree+0x78/0xd0 fs/fs_context.c:663
 vfs_get_tree+0x57/0x1d0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x24d/0x660 fs/namespace.c:3727
 path_mount+0x4a5/0xb70 fs/namespace.c:4037
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4215
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4215
 x64_sys_call+0x2b51/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 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: 0 UID: 0 PID: 11354 Comm: syz.2.2013 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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