[moderation] [block?] KCSAN: data-race in delete_from_page_cache_batch / nr_blockdev_pages (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3b47bc037bd4 Merge tag 'pinctrl-v6.7-2' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1499e654e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=585869067cd7ce59
dashboard link: https://syzkaller.appspot.com/bug?extid=177ae661472ba3eda5d1
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ax...@kernel.dk linux...@vger.kernel.org linux-...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/231e21487056/disk-3b47bc03.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eae871bb6b73/vmlinux-3b47bc03.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0c20f8f08d47/bzImage-3b47bc03.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+177ae6...@syzkaller.appspotmail.com

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

read-write to 0xffff888100630bb0 of 8 bytes by task 9946 on cpu 0:
page_cache_delete_batch mm/filemap.c:314 [inline]
delete_from_page_cache_batch+0x513/0x710 mm/filemap.c:333
truncate_inode_pages_range+0x1bd/0x6a0 mm/truncate.c:368
truncate_inode_pages+0x24/0x30 mm/truncate.c:448
kill_bdev block/bdev.c:76 [inline]
blkdev_flush_mapping+0xc0/0x1c0 block/bdev.c:632
blkdev_put_whole block/bdev.c:663 [inline]
blkdev_put+0x33a/0x470 block/bdev.c:944
bdev_release+0x2f/0x40 block/bdev.c:954
kill_block_super+0x54/0x60 fs/super.c:1670
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 0xffff888100630bb0 of 8 bytes by task 31239 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: 0x0000000000000005 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 31239 Comm: kworker/1:12 Not tainted 6.7.0-rc3-syzkaller-00033-g3b47bc037bd4 #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.