[moderation] [mm?] KCSAN: data-race in do_try_to_free_pages / shrink_node (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: dba89d1b81df Merge tag 'docs-6.9-2' of git://git.lwn.net/l..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=101b324e180000
kernel config: https://syzkaller.appspot.com/x/.config?x=8e033e6bf1fa349a
dashboard link: https://syzkaller.appspot.com/bug?extid=a16c36abe274222db6ea
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/4bfd121c5b45/disk-dba89d1b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e1b090399db0/vmlinux-dba89d1b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3fe63dba9796/bzImage-dba89d1b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a16c36...@syzkaller.appspotmail.com

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

write to 0xffff88811b88d070 of 8 bytes by task 15351 on cpu 1:
snapshot_refaults mm/vmscan.c:6175 [inline]
do_try_to_free_pages+0x93d/0xca0 mm/vmscan.c:6237
try_to_free_mem_cgroup_pages+0x1eb/0x4e0 mm/vmscan.c:6529
try_charge_memcg+0x279/0xd10 mm/memcontrol.c:2783
obj_cgroup_charge_pages+0xbd/0x1d0 mm/memcontrol.c:3302
__memcg_kmem_charge_page+0x9d/0x170 mm/memcontrol.c:3328
__alloc_pages+0x1bc/0x360 mm/page_alloc.c:4592
alloc_pages_mpol+0xb1/0x1e0 mm/mempolicy.c:2264
alloc_pages+0xe1/0x100 mm/mempolicy.c:2335
__get_free_pages+0xc/0x30 mm/page_alloc.c:4622
io_mem_alloc io_uring/io_uring.c:2807 [inline]
io_allocate_scq_urings+0x119/0x360 io_uring/io_uring.c:3761
io_uring_create+0x53c/0x940 io_uring/io_uring.c:3944
io_uring_setup io_uring/io_uring.c:4056 [inline]
__do_sys_io_uring_setup io_uring/io_uring.c:4083 [inline]
__se_sys_io_uring_setup+0x1d2/0x1e0 io_uring/io_uring.c:4077
__x64_sys_io_uring_setup+0x31/0x40 io_uring/io_uring.c:4077
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffff88811b88d070 of 8 bytes by task 15353 on cpu 0:
prepare_scan_control mm/vmscan.c:2258 [inline]
shrink_node+0x38b/0x15a0 mm/vmscan.c:5906
shrink_zones mm/vmscan.c:6152 [inline]
do_try_to_free_pages+0x3cc/0xca0 mm/vmscan.c:6214
try_to_free_mem_cgroup_pages+0x1eb/0x4e0 mm/vmscan.c:6529
try_charge_memcg+0x279/0xd10 mm/memcontrol.c:2783
obj_cgroup_charge_pages+0xbd/0x1d0 mm/memcontrol.c:3302
__memcg_kmem_charge_page+0x9d/0x170 mm/memcontrol.c:3328
__alloc_pages+0x1bc/0x360 mm/page_alloc.c:4592
alloc_pages_mpol+0xb1/0x1e0 mm/mempolicy.c:2264
alloc_pages+0xe1/0x100 mm/mempolicy.c:2335
__get_free_pages+0xc/0x30 mm/page_alloc.c:4622
io_mem_alloc io_uring/io_uring.c:2807 [inline]
io_allocate_scq_urings+0x2b8/0x360 io_uring/io_uring.c:3786
io_uring_create+0x53c/0x940 io_uring/io_uring.c:3944
io_uring_setup io_uring/io_uring.c:4056 [inline]
__do_sys_io_uring_setup io_uring/io_uring.c:4083 [inline]
__se_sys_io_uring_setup+0x1d2/0x1e0 io_uring/io_uring.c:4077
__x64_sys_io_uring_setup+0x31/0x40 io_uring/io_uring.c:4077
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

value changed: 0x000000000000003d -> 0x000000000000003e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15353 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-11752-gdba89d1b81df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================


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[syzbot]

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