EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

write to 0xffff888237c277e0 of 8 bytes by task 11 on cpu 0:
 __invalidate_bh_lrus fs/buffer.c:1414 [inline]
 invalidate_bh_lrus_cpu+0x83/0xc0 fs/buffer.c:1459
 lru_add_and_bh_lrus_drain mm/folio.c:733 [inline]
 lru_add_drain_per_cpu+0x57/0x70 mm/folio.c:752
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3479
 worker_thread+0x569/0x750 kernel/workqueue.c:3560
 kthread+0x223/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c277e0 of 8 bytes by task 3305 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1436
 smp_call_function_many_cond+0x2d1/0xbc0 kernel/smp.c:936
 on_each_cpu_cond_mask+0x35/0x50 kernel/smp.c:1169
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1445
 kill_bdev block/bdev.c:89 [inline]
 blkdev_flush_mapping+0x94/0x1a0 block/bdev.c:757
 blkdev_put_whole block/bdev.c:764 [inline]
 bdev_release+0x2c1/0x3d0 block/bdev.c:1189
 blkdev_release+0x15/0x20 block/fops.c:682
 __fput+0x29e/0x630 fs/file_table.c:512
 ____fput+0x1c/0x30 fs/file_table.c:540
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1e4/0x8c0 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x212/0x360 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88810040f6c0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3305 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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