[moderation] [mm?] KCSAN: data-race in kswapd / shrink_node

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 94ede2a3e913 profiling: remove stale percpu flip buffer va..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1184c1c9980000
kernel config: https://syzkaller.appspot.com/x/.config?x=bc4a9b665a33d32c
dashboard link: https://syzkaller.appspot.com/bug?extid=e23a38602cca31f34686
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/44ee867c2428/disk-94ede2a3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/94d1e02bfdfd/vmlinux-94ede2a3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/954c62ebb0b0/bzImage-94ede2a3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e23a38...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in kswapd / shrink_node

read-write to 0xffff88823fffd1f8 of 4 bytes by task 78 on cpu 0:
balance_pgdat mm/vmscan.c:7003 [inline]
kswapd+0x14c9/0x1820 mm/vmscan.c:7223
kthread+0x1d1/0x210 kernel/kthread.c:389
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

write to 0xffff88823fffd1f8 of 4 bytes by task 5198 on cpu 1:
shrink_node+0x1c58/0x1d40
shrink_zones mm/vmscan.c:6192 [inline]
do_try_to_free_pages+0x30e/0xb80 mm/vmscan.c:6254
try_to_free_pages+0x64f/0x950 mm/vmscan.c:6504
__perform_reclaim mm/page_alloc.c:3899 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:3921 [inline]
__alloc_pages_slowpath+0x4de/0xd70 mm/page_alloc.c:4327
__alloc_pages_noprof+0x26d/0x360 mm/page_alloc.c:4713
alloc_pages_mpol_noprof+0xb1/0x1e0 mm/mempolicy.c:2263
alloc_pages_noprof+0xe1/0x100 mm/mempolicy.c:2343
pagetable_alloc_noprof include/linux/mm.h:2868 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:70 [inline]
pte_alloc_one+0x32/0xf0 arch/x86/mm/pgtable.c:33
__do_fault+0x79/0x200 mm/memory.c:4650
do_cow_fault mm/memory.c:5091 [inline]
do_fault mm/memory.c:5193 [inline]
do_pte_missing mm/memory.c:3947 [inline]
handle_pte_fault mm/memory.c:5522 [inline]
__handle_mm_fault mm/memory.c:5665 [inline]
handle_mm_fault+0x11c9/0x2940 mm/memory.c:5833
do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
rep_stos_alternative+0x40/0x80 arch/x86/lib/clear_page_64.S:92
__clear_user arch/x86/include/asm/uaccess_64.h:172 [inline]
clear_user arch/x86/include/asm/uaccess_64.h:189 [inline]
padzero fs/binfmt_elf.c:125 [inline]
elf_load+0x394/0x520 fs/binfmt_elf.c:421
load_elf_binary+0xbf7/0x1980 fs/binfmt_elf.c:1167
search_binary_handler fs/exec.c:1821 [inline]
exec_binprm fs/exec.c:1863 [inline]
bprm_execve+0x4e6/0xc30 fs/exec.c:1914
kernel_execve+0x697/0x6d0 fs/exec.c:2081
call_usermodehelper_exec_async+0x19d/0x250 kernel/umh.c:110
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5198 Comm: modprobe Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================


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[syzbot]

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