[moderation] [mm?] KCSAN: data-race in getrusage / unmap_region

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 20cb38a7af88 Merge tag 'for-6.9-rc2-tag' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17a71bb5180000
kernel config: https://syzkaller.appspot.com/x/.config?x=ae557ecb5cabc4aa
dashboard link: https://syzkaller.appspot.com/bug?extid=bb9e84b42e2a67e8fb04
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [Liam.H...@oracle.com ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org lsto...@gmail.com vba...@suse.cz]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1c92ddc37dc2/disk-20cb38a7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2f582de438c0/vmlinux-20cb38a7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c35d06026809/bzImage-20cb38a7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bb9e84...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in getrusage / unmap_region

write to 0xffff888103ee7570 of 8 bytes by task 31495 on cpu 1:
update_hiwater_rss include/linux/mm.h:2655 [inline]
unmap_region+0x105/0x230 mm/mmap.c:2309
do_vmi_align_munmap+0x650/0x9c0 mm/mmap.c:2628
do_vmi_munmap+0x1eb/0x230 mm/mmap.c:2696
mmap_region+0x523/0x1550 mm/mmap.c:2747
do_mmap+0x6a6/0xac0 mm/mmap.c:1385
vm_mmap_pgoff+0x12f/0x250 mm/util.c:573
ksys_mmap_pgoff+0x2bd/0x340 mm/mmap.c:1431
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff888103ee7570 of 8 bytes by task 31496 on cpu 0:
get_mm_hiwater_rss include/linux/mm.h:2642 [inline]
setmax_mm_hiwater_rss include/linux/mm.h:2672 [inline]
getrusage+0xa35/0xb90 kernel/sys.c:1861
io_sq_thread+0x4d3/0xef0 io_uring/sqpoll.c:305
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x0000000000000858 -> 0x0000000000000918

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31496 Comm: iou-sqp-31495 Tainted: G W 6.9.0-rc3-syzkaller-00011-g20cb38a7af88 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================


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