[moderation] [input?] KCSAN: data-race in evdev_pass_values / evdev_read (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c3f38fa61af7 Linux 6.10-rc2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17326a1c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=8c00b51a1d411353
dashboard link: https://syzkaller.appspot.com/bug?extid=182e3fc493685d579f0d
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/eef327542baf/disk-c3f38fa6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8e83b758a6a4/vmlinux-c3f38fa6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/132dca419132/bzImage-c3f38fa6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+182e3f...@syzkaller.appspotmail.com

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

write to 0xffff888101dae808 of 4 bytes by task 4060 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_to_handler drivers/input/input.c:129 [inline]
input_pass_values+0x309/0x790 drivers/input/input.c:161
input_event_dispose+0x251/0x320 drivers/input/input.c:378
input_handle_event+0xac4/0xb00 drivers/input/input.c:406
input_inject_event+0xd1/0x100 drivers/input/input.c:465
evdev_write+0x334/0x420 drivers/input/evdev.c:530
vfs_write+0x28b/0x900 fs/read_write.c:588
ksys_write+0xeb/0x1b0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x42/0x50 fs/read_write.c:652
x64_sys_call+0x27ef/0x2d70 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 0xffff888101dae808 of 4 bytes by task 2770 on cpu 1:
evdev_read+0x1ca/0x780 drivers/input/evdev.c:574
vfs_read+0x1a2/0x6e0 fs/read_write.c:474
ksys_read+0xeb/0x1b0 fs/read_write.c:619
__do_sys_read fs/read_write.c:629 [inline]
__se_sys_read fs/read_write.c:627 [inline]
__x64_sys_read+0x42/0x50 fs/read_write.c:627
x64_sys_call+0x27e5/0x2d70 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: 0x00000017 -> 0x0000001b

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2770 Comm: acpid Not tainted 6.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================


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