[moderation] [kernel?] upstream test error: KCSAN: data-race in exit_mm / mm_update_next_owner

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3a0e92207940 Merge tag 'char-misc-6.8-rc3' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10e45a9fe80000
kernel config: https://syzkaller.appspot.com/x/.config?x=b75adb52627a8379
dashboard link: https://syzkaller.appspot.com/bug?extid=3eec1978afe3e480bf7e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [linux-...@vger.kernel.org lu...@kernel.org pet...@infradead.org tg...@linutronix.de]

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25419860252a/disk-3a0e9220.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/77d1d17b996a/vmlinux-3a0e9220.xz
kernel image: https://storage.googleapis.com/syzbot-assets/014e8a5e7336/bzImage-3a0e9220.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3eec19...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in exit_mm / mm_update_next_owner

write to 0xffff88810120c5e0 of 8 bytes by task 3110 on cpu 0:
exit_mm+0x9b/0x180 kernel/exit.c:562
do_exit+0x585/0x16d0 kernel/exit.c:858
do_group_exit+0x101/0x150 kernel/exit.c:1020
get_signal+0xf4e/0x10a0 kernel/signal.c:2893
arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
syscall_exit_to_user_mode+0x58/0x130 kernel/entry/common.c:212
do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88810120c5e0 of 8 bytes by task 3109 on cpu 1:
mm_update_next_owner+0x1a5/0x410 kernel/exit.c:494
exit_mm+0xdb/0x180 kernel/exit.c:568
do_exit+0x585/0x16d0 kernel/exit.c:858
do_group_exit+0x141/0x150 kernel/exit.c:1020
__do_sys_exit_group kernel/exit.c:1031 [inline]
__se_sys_exit_group kernel/exit.c:1029 [inline]
__x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1029
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffff888104362a00 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3109 Comm: syz-executor.0 Not tainted 6.8.0-rc2-syzkaller-00476-g3a0e92207940 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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[syzbot]

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