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BUG: KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt

write to 0xffff888103d6dc48 of 8 bytes by interrupt on cpu 0:
 ps2_interrupt+0x50d/0x550 drivers/input/serio/libps2.c:-1
 serio_interrupt+0x66/0xf0 drivers/input/serio/serio.c:967
 i8042_handle_data+0x388/0x680 drivers/input/serio/i8042.c:598
 i8042_interrupt+0x15/0x90 drivers/input/serio/i8042.c:605
 __handle_irq_event_percpu+0x8b/0x480 kernel/irq/handle.c:209
 handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:263
 handle_edge_irq+0x155/0x440 kernel/irq/chip.c:859
 generic_handle_irq_desc include/linux/irqdesc.h:188 [inline]
 handle_irq arch/x86/kernel/irq.c:209 [inline]
 call_irq_handler arch/x86/kernel/irq.c:-1 [inline]
 __common_interrupt+0x60/0xb0 arch/x86/kernel/irq.c:280
 common_interrupt+0x7e/0x90 arch/x86/kernel/irq.c:273
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:198
 free_frozen_page_commit+0x223/0x3b0 mm/page_alloc.c:2888
 free_unref_folios+0x841/0x940 mm/page_alloc.c:3079
 folios_put_refs+0x2a5/0x300 mm/swap.c:1057
 folios_put include/linux/mm.h:2183 [inline]
 __folio_batch_release+0x8c/0xb0 mm/swap.c:1117
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 shmem_undo_range+0x346/0xb60 mm/shmem.c:1149
 shmem_truncate_range mm/shmem.c:1277 [inline]
 shmem_evict_inode+0x132/0x520 mm/shmem.c:1407
 evict+0x2a5/0x510 fs/inode.c:825
 iput_final fs/inode.c:2019 [inline]
 iput+0x430/0x5a0 fs/inode.c:2068
 dentry_unlink_inode+0x24a/0x260 fs/dcache.c:479
 dentry_kill+0x184/0x500 fs/dcache.c:826
 finish_dput+0x16/0x1d0 fs/dcache.c:1001
 dput+0x48/0x50 fs/dcache.c:1042
 __fput+0x43e/0x630 fs/file_table.c:520
 ____fput+0x1c/0x30 fs/file_table.c:540
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x4a4/0x1500 kernel/exit.c:1009
 do_group_exit+0xfe/0x140 kernel/exit.c:1152
 get_signal+0xe07/0xf10 kernel/signal.c:3046
 arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x14d/0x610 kernel/entry/common.c:165
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674

read to 0xffff888103d6dc48 of 8 bytes by task 17610 on cpu 1:
 ps2_do_sendbyte+0x17e/0x320 drivers/input/serio/libps2.c:65
 __ps2_command+0x3b7/0xaa0 drivers/input/serio/libps2.c:328
 ps2_command+0x52/0x90 drivers/input/serio/libps2.c:403
 thinking_detect+0x6a/0x270 drivers/input/mouse/psmouse-base.c:652
 psmouse_do_detect drivers/input/mouse/psmouse-base.c:987 [inline]
 psmouse_try_protocol drivers/input/mouse/psmouse-base.c:1001 [inline]
 psmouse_extensions+0x2df/0x960 drivers/input/mouse/psmouse-base.c:1070
 __psmouse_reconnect+0x3da/0x8b0 drivers/input/mouse/psmouse-base.c:1685
 psmouse_reconnect+0x17/0x20 drivers/input/mouse/psmouse-base.c:1723
 serio_reconnect_driver drivers/input/serio/serio.c:52 [inline]
 serio_reconnect_port drivers/input/serio/serio.c:558 [inline]
 serio_handle_event+0x1c7/0xac0 drivers/input/serio/serio.c:201
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
 worker_thread+0x569/0x750 kernel/workqueue.c:3486
 kthread+0x221/0x270 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

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 17610 Comm: kworker/1:3 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events_long serio_handle_event
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