syzbot


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

Status: moderation: reported on 2025/08/01 04:50
Subsystems: input
[Documentation on labels]
Reported-by: syzbot+c28e542f215838132ac8@syzkaller.appspotmail.com
First crash: 26d, last: 26d
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_read (9) input 6 2 439d 449d 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 963d 988d 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 1031d 1031d 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 1849d 1849d 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 1602d 1602d 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 349d 349d 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 1073d 1113d 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 778d 851d 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 172d 172d 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 659d 626d 0/29 auto-obsoleted due to no activity on 2023/12/24 00:01
upstream KCSAN: data-race in evdev_pass_values / evdev_read (3) input 6 78 1154d 1197d 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 0xffff88810334f008 of 4 bytes by task 17801 on cpu 0:
 __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+0x120/0x390 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+0xba/0xf0 drivers/input/input.c:423
 evdev_write+0x1fa/0x290 drivers/input/evdev.c:528
 vfs_write+0x269/0x8e0 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 0xffff88810334f008 of 4 bytes by task 2977 on cpu 1:
 evdev_read+0x158/0x5e0 drivers/input/evdev.c:572
 vfs_read+0x19d/0x6f0 fs/read_write.c:570
 ksys_read+0xda/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+0x27bc/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:1
 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: 0x0000003e -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2977 Comm: acpid Not tainted 6.16.0-syzkaller-08685-g260f6f4fda93 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/01 04:49 upstream 260f6f4fda93 0c075d67 .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.