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BUG: KCSAN: data-race in __filemap_remove_folio / folio_mapping

write to 0xffffea000597f6d8 of 8 bytes by task 21778 on cpu 0:
 page_cache_delete mm/filemap.c:145 [inline]
 __filemap_remove_folio+0x201/0x300 mm/filemap.c:228
 filemap_remove_folio+0x6d/0x1d0 mm/filemap.c:257
 truncate_inode_folio+0x42/0x50 mm/truncate.c:176
 shmem_undo_range+0x28a/0xb10 mm/shmem.c:1133
 shmem_truncate_range mm/shmem.c:1249 [inline]
 shmem_evict_inode+0x12e/0x510 mm/shmem.c:1379
 evict+0x2af/0x510 fs/inode.c:837
 iput_final fs/inode.c:1954 [inline]
 iput+0x4b9/0x650 fs/inode.c:2006
 dentry_unlink_inode+0x24f/0x260 fs/dcache.c:467
 __dentry_kill+0x13f/0x460 fs/dcache.c:670
 finish_dput+0x2b/0x200 fs/dcache.c:879
 dput+0x52/0x60 fs/dcache.c:928
 __fput+0x444/0x650 fs/file_table.c:476
 ____fput+0x1c/0x30 fs/file_table.c:496
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x466/0x1590 kernel/exit.c:971
 do_group_exit+0xfe/0x140 kernel/exit.c:1112
 get_signal+0xe4f/0xf60 kernel/signal.c:3034
 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 0xffffea000597f6d8 of 8 bytes by task 21779 on cpu 1:
 folio_mapping+0xa1/0xe0 mm/util.c:703
 folio_evictable mm/internal.h:499 [inline]
 move_folios_to_lru+0x128/0x6d0 mm/vmscan.c:1900
 evict_folios+0x31e6/0x35b0 mm/vmscan.c:4741
 try_to_shrink_lruvec+0x5f6/0x960 mm/vmscan.c:4874
 lru_gen_shrink_lruvec mm/vmscan.c:5023 [inline]
 shrink_lruvec+0x24e/0x1bc0 mm/vmscan.c:5784
 shrink_node_memcgs mm/vmscan.c:6020 [inline]
 shrink_node+0x68e/0x2000 mm/vmscan.c:6061
 shrink_zones mm/vmscan.c:6300 [inline]
 do_try_to_free_pages+0x404/0xcc0 mm/vmscan.c:6362
 try_to_free_mem_cgroup_pages+0x222/0x470 mm/vmscan.c:6690
 try_charge_memcg+0x37e/0xa10 mm/memcontrol.c:2388
 try_charge mm/memcontrol.c:2530 [inline]
 charge_memcg mm/memcontrol.c:4728 [inline]
 __mem_cgroup_charge+0x65/0x150 mm/memcontrol.c:4745
 mem_cgroup_charge include/linux/memcontrol.h:663 [inline]
 shmem_alloc_and_add_folio mm/shmem.c:1942 [inline]
 shmem_get_folio_gfp+0x47b/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+0xa7d/0xdb0 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

value changed: 0xffff888103d61360 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21779 Comm: syz.5.4498 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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