KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt

Status: moderation: reported on 2026/07/24 18:43
Subsystems: input
Labels: race:benign prio:low
[Documentation on labels]
Reported-by: syzbot+96605ccb04166cb6cfe8@syzkaller.appspotmail.com
First crash: 3d01h, last: 4h21m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a54ac6e2 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt 2026/07/26 01:50 2026/07/26 01:50 2026/07/26 02:20 492bab15

			
		
f55a2969 assessment-kcsan Benign: ✅ KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt 2026/07/24 18:42 2026/07/24 18:42 2026/07/24 18:45 1bdb5c57

			
		

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt

write to 0xffff888103de2448 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
 check_kcov_mode kernel/kcov.c:185 [inline]
 __sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217
 vmf_can_call_fault mm/memory.c:3797 [inline]
 do_read_fault mm/memory.c:5856 [inline]
 do_fault mm/memory.c:5994 [inline]
 do_pte_missing mm/memory.c:4566 [inline]
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0x15d3/0x2da0 mm/memory.c:6686
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x129c/0x1f10 mm/gup.c:1428
 populate_vma_page_range mm/gup.c:1860 [inline]
 __mm_populate+0x242/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:4171 [inline]
 vm_mmap_pgoff+0x23b/0x2d0 mm/util.c:586
 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:606
 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103de2448 of 8 bytes by task 3375 on cpu 1:
 ps2_do_sendbyte+0x10b/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
 synaptics_detect+0x5e/0x130 drivers/input/mouse/synaptics.c:102
 psmouse_do_detect drivers/input/mouse/psmouse-base.c:987 [inline]
 psmouse_extensions+0x4df/0x960 drivers/input/mouse/psmouse-base.c:1082
 __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: 3375 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
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/27 15:41 upstream f5098b6bae76 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/27 15:38 upstream f5098b6bae76 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/27 10:31 upstream f5098b6bae76 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/27 03:03 upstream 4235cb24ec1e 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/26 09:55 upstream 3dab139d4795 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/26 06:08 upstream 0ce37745d4bf 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/26 06:06 upstream 0ce37745d4bf 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/26 06:01 upstream 0ce37745d4bf 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/26 00:27 upstream 0ce37745d4bf 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/25 10:11 upstream e2a936998ab2 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
2026/07/24 18:42 upstream 48a5a7ab8d6a dd737a83 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ps2_do_sendbyte / ps2_interrupt
* Struck through repros no longer work on HEAD.