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BUG: KCSAN: data-race in __filemap_add_folio / nr_blockdev_pages

read-write to 0xffff88810048af78 of 8 bytes by task 11159 on cpu 1:
 __filemap_add_folio+0x66e/0x880 mm/filemap.c:919
 filemap_add_folio+0x1d3/0x350 mm/filemap.c:966
 do_read_cache_folio+0xd9/0x600 mm/filemap.c:4107
 read_cache_folio+0x3c/0x50 mm/filemap.c:4172
 read_mapping_folio include/linux/pagemap.h:1015 [inline]
 read_part_sector+0x6f/0x150 block/partitions/core.c:724
 read_lba+0x100/0x1e0 block/partitions/efi.c:247
 find_valid_gpt block/partitions/efi.c:602 [inline]
 efi_partition+0x1ca/0x1100 block/partitions/efi.c:719
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x532/0xe20 block/partitions/core.c:695
 loop_reread_partitions drivers/block/loop.c:443 [inline]
 loop_set_status+0x5af/0x670 drivers/block/loop.c:1272
 loop_set_status64 drivers/block/loop.c:1368 [inline]
 lo_ioctl+0x66d/0x1390 drivers/block/loop.c:1554
 blkdev_ioctl+0x387/0x460 block/ioctl.c:797
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810048af78 of 8 bytes by task 8111 on cpu 0:
 nr_blockdev_pages+0x7e/0xd0 block/bdev.c:526
 si_meminfo+0x87/0xd0 mm/show_mem.c:80
 update_defense_level+0x44/0x5c0 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:3322 [inline]
 process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
 worker_thread+0x569/0x750 kernel/workqueue.c:3486
 kthread+0x221/0x270 kernel/kthread.c:436
 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000000000 -> 0x0000000000000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8111 Comm: kworker/0:8 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_long defense_work_handler
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