[moderation] [mm?] KCSAN: data-race in getrusage / try_to_unmap_one (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 67a993863163 Merge tag 'v6.16-p6' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1722c982580000
kernel config: https://syzkaller.appspot.com/x/.config?x=39acdbb3c95d37e5
dashboard link: https://syzkaller.appspot.com/bug?extid=5f5b43d7c7d33976e7ef
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
CC: [Liam.H...@oracle.com ak...@linux-foundation.org da...@redhat.com harr...@oracle.com linux-...@vger.kernel.org linu...@kvack.org lorenzo...@oracle.com ri...@surriel.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/351756923090/disk-67a99386.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f2762f676256/vmlinux-67a99386.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bc628869dc44/bzImage-67a99386.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5f5b43...@syzkaller.appspotmail.com

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

write to 0xffff88811b3cf9f0 of 8 bytes by task 12220 on cpu 1:
update_hiwater_rss include/linux/mm.h:2631 [inline]
try_to_unmap_one+0xf63/0x21d0 mm/rmap.c:2061
__rmap_walk_file+0x1e9/0x2b0 mm/rmap.c:2897
try_to_unmap+0x1ae/0x1e0 mm/rmap.c:-1
shrink_folio_list+0x11b9/0x2560 mm/vmscan.c:1389
reclaim_folio_list+0x83/0x2b0 mm/vmscan.c:2232
reclaim_pages+0x215/0x270 mm/vmscan.c:2269
madvise_cold_or_pageout_pte_range+0xd0d/0xd80 mm/madvise.c:564
walk_pmd_range mm/pagewalk.c:130 [inline]
walk_pud_range mm/pagewalk.c:226 [inline]
walk_p4d_range mm/pagewalk.c:264 [inline]
walk_pgd_range+0xa47/0x14e0 mm/pagewalk.c:305
__walk_page_range+0xdd/0x340 mm/pagewalk.c:412
walk_page_range_mm+0x352/0x4a0 mm/pagewalk.c:505
walk_page_range+0x56/0x70 mm/pagewalk.c:584
madvise_vma_behavior include/asm-generic/tlb.h:-1 [inline]
madvise_walk_vmas mm/madvise.c:1541 [inline]
madvise_do_behavior+0x1a45/0x1f20 mm/madvise.c:1733
do_madvise+0x103/0x190 mm/madvise.c:1826
__do_sys_madvise mm/madvise.c:1835 [inline]
__se_sys_madvise mm/madvise.c:1833 [inline]
__x64_sys_madvise+0x64/0x80 mm/madvise.c:1833
x64_sys_call+0x2455/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:29
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b3cf9f0 of 8 bytes by task 12218 on cpu 0:
get_mm_hiwater_rss include/linux/mm.h:2618 [inline]
setmax_mm_hiwater_rss include/linux/mm.h:2648 [inline]
getrusage+0xa52/0xbb0 kernel/sys.c:1877
io_sq_thread+0x5dd/0x1180 io_uring/sqpoll.c:320
ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000000021b8 -> 0x00000000000025a2

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 12218 Comm: iou-sqp-12215 Tainted: G W 6.16.0-rc3-syzkaller-00190-g67a993863163 #0 PREEMPT(voluntary)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================


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[syzbot]

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