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BUG: KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt

write to 0xffff888103d9ac48 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
 kcsan_setup_watchpoint+0x429/0x4a0 kernel/kcsan/core.c:714
 free_pages_and_swap_cache+0x246/0x3b0 mm/swap_state.c:639
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0x54f/0x6b0 mm/mmu_gather.c:404
 zap_pte_range mm/memory.c:2067 [inline]
 zap_pmd_range mm/memory.c:2114 [inline]
 zap_pud_range mm/memory.c:2142 [inline]
 zap_p4d_range mm/memory.c:2163 [inline]
 __zap_vma_range+0x259f/0x2c50 mm/memory.c:2203
 unmap_vmas+0x1fb/0x2e0 mm/memory.c:2272
 exit_mmap+0x1a2/0x5e0 mm/mmap.c:1315
 __mmput+0x28/0x1c0 kernel/fork.c:1191
 mmput+0x3b/0x50 kernel/fork.c:1214
 exit_mm+0x11b/0x1b0 kernel/exit.c:586
 do_exit+0x437/0x14f0 kernel/exit.c:967
 do_group_exit+0xfe/0x140 kernel/exit.c:1123
 get_signal+0xe02/0xf00 kernel/signal.c:3112
 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+0x15d/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:343 [inline]
 do_syscall_64+0x212/0x360 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103d9ac48 of 8 bytes by task 6507 on cpu 1:
 ps2_do_sendbyte+0x106/0x320 drivers/input/serio/libps2.c:65
 __ps2_command+0x3b9/0xa90 drivers/input/serio/libps2.c:328
 ps2_command+0x52/0x90 drivers/input/serio/libps2.c:403
 psmouse_set_resolution+0x7d/0xd0 drivers/input/mouse/psmouse-base.c:455
 psmouse_initialize drivers/input/mouse/psmouse-base.c:1271 [inline]
 psmouse_attr_set_protocol+0x555/0xad0 drivers/input/mouse/psmouse-base.c:1924
 psmouse_attr_set_helper+0x2a3/0x450 drivers/input/mouse/psmouse-base.c:1815
 dev_attr_store+0x4a/0x70 drivers/base/core.c:2509
 sysfs_kf_write+0xfe/0x120 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x1d2/0x2e0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x57a/0x990 fs/read_write.c:687
 ksys_write+0xdc/0x1a0 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:747
 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6507 Comm: syz.0.1105 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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input: PS/2 BYD TouchPad as /devices/platform/i8042/serio1/input/input5