syzbot


KCSAN: data-race in evdev_pass_values / evdev_read (13)

Status: moderation: reported on 2026/01/22 19:06
Subsystems: input
[Documentation on labels]
Reported-by: syzbot+1b327485934adf39955b@syzkaller.appspotmail.com
First crash: 5d03h, last: 5d03h
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in evdev_pass_values / evdev_read (9) input 6 2 593d 603d 0/29 auto-obsoleted due to no activity on 2024/07/18 19:14
upstream KCSAN: data-race in evdev_pass_values / evdev_read (6) input 6 5 1117d 1142d 0/29 auto-obsoleted due to no activity on 2023/02/12 16:10
upstream KCSAN: data-race in evdev_pass_values / evdev_read (5) input 6 1 1185d 1185d 0/29 auto-obsoleted due to no activity on 2022/12/04 22:10
upstream KCSAN: data-race in evdev_pass_values / evdev_read input 6 1 2002d 2002d 0/29 auto-closed as invalid on 2020/09/08 04:08
upstream KCSAN: data-race in evdev_pass_values / evdev_read (2) input 6 1 1756d 1756d 0/29 auto-closed as invalid on 2021/05/12 19:26
upstream KCSAN: data-race in evdev_pass_values / evdev_read (10) input 6 1 503d 503d 0/29 auto-obsoleted due to no activity on 2024/10/16 22:12
upstream KCSAN: data-race in evdev_pass_values / evdev_read (4) input 6 4 1227d 1266d 0/29 auto-obsoleted due to no activity on 2022/10/23 08:11
upstream KCSAN: data-race in evdev_pass_values / evdev_read (7) input 6 28 932d 1005d 0/29 auto-obsoleted due to no activity on 2023/08/14 19:50
upstream KCSAN: data-race in evdev_pass_values / evdev_read (11) input 6 1 325d 325d 0/29 auto-obsoleted due to no activity on 2025/05/03 03:24
upstream KCSAN: data-race in evdev_pass_values / evdev_read (8) input 6 16 813d 779d 0/29 auto-obsoleted due to no activity on 2023/12/24 00:01
upstream KCSAN: data-race in evdev_pass_values / evdev_read (12) input 6 4 67d 179d 0/29 auto-obsoleted due to no activity on 2026/01/16 02:34
upstream KCSAN: data-race in evdev_pass_values / evdev_read (3) input 6 78 1307d 1351d 0/29 auto-closed as invalid on 2022/08/03 23:33

Sample crash report:
==================================================================
BUG: KCSAN: data-race in evdev_pass_values / evdev_read

write to 0xffff888104842008 of 4 bytes by task 8439 on cpu 1:
 __pass_event drivers/input/evdev.c:239 [inline]
 evdev_pass_values+0x387/0x4e0 drivers/input/evdev.c:278
 evdev_events+0x8e/0xd0 drivers/input/evdev.c:306
 input_pass_values+0x123/0x390 drivers/input/input.c:128
 input_event_dispose+0x248/0x320 drivers/input/input.c:342
 input_handle_event+0x9e8/0xa20 drivers/input/input.c:370
 input_inject_event+0xbc/0x120 drivers/input/input.c:424
 evdev_write+0x224/0x2b0 drivers/input/evdev.c:528
 vfs_write+0x269/0x9f0 fs/read_write.c:684
 ksys_write+0xdc/0x1a0 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:746
 x64_sys_call+0x2847/0x3000 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104842008 of 4 bytes by task 2991 on cpu 0:
 evdev_read+0x157/0x5e0 drivers/input/evdev.c:572
 vfs_read+0x1ab/0x7f0 fs/read_write.c:570
 ksys_read+0xdc/0x1a0 fs/read_write.c:715
 __do_sys_read fs/read_write.c:724 [inline]
 __se_sys_read fs/read_write.c:722 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:722
 x64_sys_call+0x2889/0x3000 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000004

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2991 Comm: acpid Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/22 19:06 upstream a66191c590b3 82c9c083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in evdev_pass_values / evdev_read
* Struck through repros no longer work on HEAD.