[moderation] [mm?] KCSAN: data-race in __filemap_remove_folio / nr_blockdev_pages (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=149a190ee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac34c1f29a8029df
dashboard link: https://syzkaller.appspot.com/bug?extid=b84d1b89a5b93d83d240
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/233be5f65dd2/disk-bee0e776.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/94423738a289/vmlinux-bee0e776.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b977463fa9a/bzImage-bee0e776.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b84d1b...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __filemap_remove_folio / nr_blockdev_pages

read-write to 0xffff888100631e70 of 8 bytes by task 4491 on cpu 0:
page_cache_delete mm/filemap.c:144 [inline]
__filemap_remove_folio+0x1d1/0x2d0 mm/filemap.c:222
__remove_mapping+0x341/0x460 mm/vmscan.c:756
remove_mapping+0x22/0x90 mm/vmscan.c:789
mapping_evict_folio mm/truncate.c:281 [inline]
mapping_try_invalidate+0x286/0x3d0 mm/truncate.c:520
invalidate_mapping_pages+0x27/0x30 mm/truncate.c:558
invalidate_bdev+0x65/0x70 block/bdev.c:87
ext4_put_super+0x51b/0x7e0 fs/ext4/super.c:1361
generic_shutdown_super+0xdb/0x210 fs/super.c:696
kill_block_super+0x2a/0x60 fs/super.c:1667
ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7330
deactivate_locked_super+0x7a/0x1c0 fs/super.c:484
deactivate_super+0x9b/0xb0 fs/super.c:517
cleanup_mnt+0x272/0x2e0 fs/namespace.c:1256
__cleanup_mnt+0x19/0x20 fs/namespace.c:1263
task_work_run+0x135/0x1a0 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xd6/0xe0 kernel/entry/common.c:171
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888100631e70 of 8 bytes by task 3160 on cpu 1:
nr_blockdev_pages+0x7c/0xd0 block/bdev.c:443
si_meminfo+0x87/0xd0 mm/show_mem.c:80
update_defense_level+0x46/0x600 net/netfilter/ipvs/ip_vs_ctl.c:101
defense_work_handler+0x1f/0x80 net/netfilter/ipvs/ip_vs_ctl.c:235
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
worker_thread+0x525/0x730 kernel/workqueue.c:2784
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x000000000000000c -> 0x0000000000000009

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3160 Comm: kworker/1:2 Tainted: G W 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: events_long defense_work_handler
==================================================================


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[syzbot]

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