EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237c299a4 of 4 bytes by task 3381 on cpu 0:
 wq_worker_running+0x95/0x120 kernel/workqueue.c:1400
 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x414/0xa50 kernel/locking/mutex.c:746
 __mutex_lock_slowpath+0xa/0x10 kernel/locking/mutex.c:1033
 mutex_lock+0x27/0x30 kernel/locking/mutex.c:277
 exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 synchronize_rcu_expedited+0x18a/0x790 kernel/rcu/tree_exp.h:998
 synchronize_rcu+0x45/0x320 kernel/rcu/tree.c:3311
 key_garbage_collector+0x77f/0x8f0 security/keys/gc.c:297
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c299a4 of 4 bytes by task 3303 on cpu 1:
 need_more_worker kernel/workqueue.c:934 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1240
 __queue_work+0x8d6/0xb60 kernel/workqueue.c:2342
 queue_work_on+0xd1/0x160 kernel/workqueue.c:2392
 __lru_add_drain_all+0x2c6/0x3f0 mm/swap.c:869
 lru_add_drain_all+0x10/0x20 mm/swap.c:883
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1343
 generic_shutdown_super+0xe3/0x210 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7393
 deactivate_locked_super+0x72/0x1c0 fs/super.c:473
 deactivate_super+0x97/0xa0 fs/super.c:506
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1435
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1442
 task_work_run+0x12e/0x1a0 kernel/task_work.c:227
 resume_user_mode_work+0x6a/0x70 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x77/0xb0 kernel/entry/common.c:218
 do_syscall_64+0xdd/0x1a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3303 Comm: syz-executor Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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