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BUG: KCSAN: data-race in __lru_add_drain_all / folio_add_lru

read-write to 0xffff888237c26468 of 1 bytes by task 17064 on cpu 0:
 folio_batch_add include/linux/pagevec.h:77 [inline]
 __folio_batch_add_and_move mm/swap.c:194 [inline]
 folio_add_lru+0xa4/0x1e0 mm/swap.c:511
 shmem_alloc_and_add_folio mm/shmem.c:1991 [inline]
 shmem_get_folio_gfp+0x7b0/0xd60 mm/shmem.c:2556
 shmem_get_folio mm/shmem.c:2662 [inline]
 shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3315
 generic_perform_write+0x183/0x490 mm/filemap.c:4314
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3490
 __kernel_write_iter+0x319/0x590 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1298 [inline]
 dump_user_range+0x63e/0x8f0 fs/coredump.c:1372
 elf_core_dump+0x21a2/0x2330 fs/binfmt_elf.c:2111
 coredump_write+0xacf/0xdf0 fs/coredump.c:1049
 do_coredump fs/coredump.c:1126 [inline]
 vfs_coredump+0x26bc/0x3120 fs/coredump.c:1200
 get_signal+0xd7b/0xf60 kernel/signal.c:3019
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
 irqentry_exit+0xf7/0x510 kernel/entry/common.c:196
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

read to 0xffff888237c26468 of 1 bytes by task 3010 on cpu 1:
 folio_batch_count include/linux/pagevec.h:56 [inline]
 cpu_needs_drain mm/swap.c:780 [inline]
 __lru_add_drain_all+0x17e/0x450 mm/swap.c:877
 lru_add_drain_all+0x10/0x20 mm/swap.c:893
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 bdev_disk_changed+0xeb/0xcb0 block/partitions/core.c:657
 blkdev_get_whole+0x1f5/0x2d0 block/bdev.c:765
 bdev_open+0x280/0x7e0 block/bdev.c:974
 bdev_file_open_by_dev+0x1e6/0x250 block/bdev.c:1076
 disk_scan_partitions+0x148/0x1b0 block/genhd.c:387
 blkdev_common_ioctl+0x1236/0x20b0 block/ioctl.c:707
 blkdev_ioctl+0x31f/0x460 block/ioctl.c:786
 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+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x13 -> 0x18

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3010 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 loop6: p1 < > p3 p4 < >
loop6: p3 size 33554432 extends beyond EOD, truncated