[moderation] [input?] KCSAN: data-race in evdev_pass_values / evdev_read (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 21e4543a2e2f Merge tag 'slab-for-6.14-rc5' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=100cea54580000
kernel config: https://syzkaller.appspot.com/x/.config?x=523b0e2f15224775
dashboard link: https://syzkaller.appspot.com/bug?extid=108502f3201f9b0ed5e1
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [dmitry....@gmail.com linux...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/361a99f9a2c6/disk-21e4543a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f77e1424d13c/vmlinux-21e4543a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9cd5e20f8f94/bzImage-21e4543a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+108502...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in evdev_pass_values / evdev_read

write to 0xffff888104580808 of 4 bytes by task 13371 on cpu 0:
__pass_event drivers/input/evdev.c:239 [inline]
evdev_pass_values+0x3ac/0x510 drivers/input/evdev.c:278
evdev_events+0x90/0xd0 drivers/input/evdev.c:306
input_pass_values+0x11a/0x390 drivers/input/input.c:127
input_event_dispose+0x232/0x300 drivers/input/input.c:341
input_handle_event+0xac4/0xb00 drivers/input/input.c:369
input_inject_event+0xd1/0x110 drivers/input/input.c:423
evdev_write+0x33f/0x440 drivers/input/evdev.c:528
vfs_write+0x27d/0x920 fs/read_write.c:677
ksys_write+0xe8/0x1b0 fs/read_write.c:731
__do_sys_write fs/read_write.c:742 [inline]
__se_sys_write fs/read_write.c:739 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:739
x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104580808 of 4 bytes by task 2985 on cpu 1:
evdev_read+0x1c4/0x780 drivers/input/evdev.c:572
vfs_read+0x19b/0x6f0 fs/read_write.c:563
ksys_read+0xe8/0x1b0 fs/read_write.c:708
__do_sys_read fs/read_write.c:717 [inline]
__se_sys_read fs/read_write.c:715 [inline]
__x64_sys_read+0x42/0x50 fs/read_write.c:715
x64_sys_call+0x2874/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000003 -> 0x00000005

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2985 Comm: acpid Not tainted 6.14.0-rc5-syzkaller-00214-g21e4543a2e2f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.