syzbot


KCSAN: data-race in evdev_pass_values / evdev_poll (12)

Status: moderation: reported on 2025/08/27 20:57
Subsystems: input
[Documentation on labels]
Reported-by: syzbot+cb962545025ba25fcb26@syzkaller.appspotmail.com
First crash: 5d11h, last: 5d11h
Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (10) input 6 2 252d 254d 0/29 auto-obsoleted due to no activity on 2025/02/17 08:57
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (3) input 6 2 1045d 1057d 0/29 auto-obsoleted due to no activity on 2022/11/27 08:01
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (11) input 6 2 107d 113d 0/29 auto-obsoleted due to no activity on 2025/07/12 11:09
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (8) input 6 1 521d 521d 0/29 auto-obsoleted due to no activity on 2024/05/04 08:18
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (9) input 6 6 445d 473d 0/29 auto-obsoleted due to no activity on 2024/07/18 19:14
upstream KCSAN: data-race in evdev_pass_values / evdev_poll input 6 65 1165d 1413d 0/29 auto-closed as invalid on 2022/07/29 11:48
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (5) input 6 16 803d 835d 0/29 auto-obsoleted due to no activity on 2023/07/27 03:31
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (4) input 6 7 966d 991d 0/29 auto-obsoleted due to no activity on 2023/03/10 09:08
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (7) input 6 5 618d 631d 0/29 auto-obsoleted due to no activity on 2024/01/28 04:16
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (6) input 6 5 726d 745d 0/29 auto-obsoleted due to no activity on 2023/10/11 10:42
upstream KCSAN: data-race in evdev_pass_values / evdev_poll (2) input 6 2 1098d 1100d 0/29 auto-closed as invalid on 2022/10/04 21:56

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

write to 0xffff888100378008 of 4 bytes by task 5994 on cpu 1:
 __pass_event drivers/input/evdev.c:239 [inline]
 evdev_pass_values+0x3d4/0x510 drivers/input/evdev.c:278
 evdev_events+0x8e/0xd0 drivers/input/evdev.c:306
 input_pass_values+0x123/0x390 drivers/input/input.c:127
 input_event_dispose+0x248/0x320 drivers/input/input.c:341
 input_handle_event+0x9e8/0xa20 drivers/input/input.c:369
 input_inject_event+0xbc/0x120 drivers/input/input.c:423
 evdev_write+0x1fa/0x290 drivers/input/evdev.c:528
 vfs_write+0x269/0x960 fs/read_write.c:684
 ksys_write+0xda/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+0x27fe/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100378008 of 4 bytes by task 2977 on cpu 0:
 evdev_poll+0xc4/0x100 drivers/input/evdev.c:621
 vfs_poll include/linux/poll.h:82 [inline]
 select_poll_one fs/select.c:480 [inline]
 do_select+0x8ee/0xf50 fs/select.c:536
 core_sys_select+0x3d7/0x6e0 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:802 [inline]
 __se_sys_pselect6+0x216/0x280 fs/select.c:793
 __x64_sys_pselect6+0x78/0x90 fs/select.c:793
 x64_sys_call+0x28b9/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:271
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000005

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2977 Comm: acpid Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/27 20:57 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in evdev_pass_values / evdev_poll
* Struck through repros no longer work on HEAD.