[moderation] [kernel?] KCSAN: data-race in copy_process / free_pid (10)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f2e8a57ee903 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=115e5e6ce80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac34c1f29a8029df
dashboard link: https://syzkaller.appspot.com/bug?extid=e947504c223a9c9457fa
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [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/e81f2b8d4585/disk-f2e8a57e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/614fba6a34bb/vmlinux-f2e8a57e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/01cf31246ce8/bzImage-f2e8a57e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e94750...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in copy_process / free_pid

read-write to 0xffffffff85a57c88 of 4 bytes by task 14213 on cpu 1:
free_pid+0x80/0x170 kernel/pid.c:139
copy_process+0x1aed/0x20a0 kernel/fork.c:2747
kernel_clone+0x169/0x560 kernel/fork.c:2907
__do_sys_clone3 kernel/fork.c:3208 [inline]
__se_sys_clone3+0x1b5/0x1f0 kernel/fork.c:3192
__x64_sys_clone3+0x31/0x40 kernel/fork.c:3192
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffffffff85a57c88 of 4 bytes by task 2 on cpu 0:
copy_process+0x1700/0x20a0 kernel/fork.c:2653
kernel_clone+0x169/0x560 kernel/fork.c:2907
kernel_thread+0xb4/0xe0 kernel/fork.c:2969
create_kthread kernel/kthread.c:411 [inline]
kthreadd+0x28a/0x330 kernel/kthread.c:764
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x8000019c -> 0x8000019b

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.7.0-rc4-syzkaller-00358-gf2e8a57ee903 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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