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BUG: KCSAN: data-race in __filemap_remove_folio / folio_mapping

write to 0xffffea0005673958 of 8 bytes by task 8539 on cpu 1:
 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+0x26d/0xb10 mm/shmem.c:1145
 shmem_truncate_range mm/shmem.c:1277 [inline]
 shmem_evict_inode+0x12e/0x510 mm/shmem.c:1407
 evict+0x2af/0x510 fs/inode.c:846
 iput_final fs/inode.c:1966 [inline]
 iput+0x41a/0x580 fs/inode.c:2015
 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:477
 ____fput+0x1c/0x30 fs/file_table.c:497
 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:64 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:98 [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+0xf7/0x520 kernel/entry/common.c:219
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

read to 0xffffea0005673958 of 8 bytes by task 8728 on cpu 0:
 folio_mapping+0xa1/0xe0 mm/util.c:703
 folio_evictable mm/internal.h:566 [inline]
 sort_folio mm/vmscan.c:4442 [inline]
 scan_folios mm/vmscan.c:4570 [inline]
 isolate_folios mm/vmscan.c:4666 [inline]
 evict_folios+0xde9/0x35b0 mm/vmscan.c:4696
 try_to_shrink_lruvec+0x606/0x980 mm/vmscan.c:4871
 lru_gen_shrink_lruvec mm/vmscan.c:5020 [inline]
 shrink_lruvec+0x24e/0x1b40 mm/vmscan.c:5774
 shrink_node_memcgs mm/vmscan.c:6010 [inline]
 shrink_node+0x67e/0x20c0 mm/vmscan.c:6051
 shrink_zones mm/vmscan.c:6290 [inline]
 do_try_to_free_pages+0x408/0xc80 mm/vmscan.c:6352
 try_to_free_mem_cgroup_pages+0x1f5/0x450 mm/vmscan.c:6673
 try_charge_memcg+0x37e/0xa10 mm/memcontrol.c:2414
 obj_cgroup_charge_pages+0x23/0xc0 mm/memcontrol.c:2857
 __memcg_kmem_charge_page+0x9e/0x170 mm/memcontrol.c:2901
 __alloc_frozen_pages_noprof+0x18a/0x350 mm/page_alloc.c:5261
 alloc_pages_mpol+0xb3/0x260 mm/mempolicy.c:2485
 alloc_frozen_pages_noprof mm/mempolicy.c:2556 [inline]
 alloc_pages_noprof+0x8f/0x130 mm/mempolicy.c:2576
 vm_area_alloc_pages mm/vmalloc.c:3731 [inline]
 __vmalloc_area_node mm/vmalloc.c:3876 [inline]
 __vmalloc_node_range_noprof+0xa46/0x12b0 mm/vmalloc.c:4064
 __bpf_map_area_alloc kernel/bpf/syscall.c:404 [inline]
 bpf_map_area_alloc+0xfa/0x140 kernel/bpf/syscall.c:411
 dev_map_create_hash kernel/bpf/devmap.c:95 [inline]
 dev_map_init_map kernel/bpf/devmap.c:145 [inline]
 dev_map_alloc+0xdd/0x380 kernel/bpf/devmap.c:171
 map_create+0x862/0xda0 kernel/bpf/syscall.c:1507
 __sys_bpf+0x5c8/0x7e0 kernel/bpf/syscall.c:6211
 __do_sys_bpf kernel/bpf/syscall.c:6342 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6340 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6340
 x64_sys_call+0x10cb/0x3020 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811f56b928 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8728 Comm: syz.3.1301 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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