syzbot

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BUG: KCSAN: data-race in __filemap_remove_folio / nr_blockdev_pages

read-write to 0xffff888100631830 of 8 bytes by task 3318 on cpu 1:
 page_cache_delete mm/filemap.c:155 [inline]
 __filemap_remove_folio+0x1c5/0x2c0 mm/filemap.c:233
 __remove_mapping+0x33f/0x470 mm/vmscan.c:791
 remove_mapping+0x22/0x90 mm/vmscan.c:824
 mapping_evict_folio mm/truncate.c:277 [inline]
 mapping_try_invalidate+0x266/0x3f0 mm/truncate.c:496
 invalidate_mapping_pages+0x27/0x40 mm/truncate.c:538
 invalidate_bdev+0x58/0x70 block/bdev.c:102
 ext4_put_super+0x571/0x840 fs/ext4/super.c:1349
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7320
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x268/0x2e0 fs/namespace.c:1373
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1380
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100631830 of 8 bytes by task 3558 on cpu 0:
 nr_blockdev_pages+0x7c/0xd0 block/bdev.c:482
 si_meminfo+0x87/0xd0 mm/show_mem.c:80
 update_defense_level+0x49/0x5b0 net/netfilter/ipvs/ip_vs_ctl.c:102
 defense_work_handler+0x1f/0x80 net/netfilter/ipvs/ip_vs_ctl.c:235
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 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

value changed: 0x0000000000000004 -> 0x0000000000000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3558 Comm: kworker/0:5 Not tainted 6.12.0-rc6-syzkaller-00272-gda4373fbcf00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_long defense_work_handler
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