==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / folio_mapping

write to 0xffffea0004b012d8 of 8 bytes by task 9533 on cpu 0:
 page_cache_delete_batch mm/filemap.c:309 [inline]
 delete_from_page_cache_batch+0x2f6/0x6f0 mm/filemap.c:335
 truncate_inode_pages_range+0x1ba/0x780 mm/truncate.c:405
 truncate_inode_pages+0x24/0x30 mm/truncate.c:485
 ext4_truncate_failed_write fs/ext4/truncate.h:21 [inline]
 ext4_write_end+0x541/0x730 fs/ext4/inode.c:1486
 ext4_da_write_end+0x65/0x800 fs/ext4/inode.c:3277
 generic_perform_write+0x312/0x490 mm/filemap.c:4275
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_file_write_iter+0x387/0xf60 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x52a/0x960 fs/read_write.c:686
 ksys_pwrite64 fs/read_write.c:793 [inline]
 __do_sys_pwrite64 fs/read_write.c:801 [inline]
 __se_sys_pwrite64 fs/read_write.c:798 [inline]
 __x64_sys_pwrite64+0xfd/0x150 fs/read_write.c:798
 x64_sys_call+0xc4d/0x3000 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffea0004b012d8 of 8 bytes by task 9528 on cpu 1:
 folio_mapping+0xa1/0xe0 mm/util.c:703
 folio_evictable mm/internal.h:499 [inline]
 lru_add+0x8d/0x480 mm/swap.c:136
 folio_batch_move_lru+0x1c5/0x280 mm/swap.c:172
 __folio_batch_add_and_move mm/swap.c:196 [inline]
 folio_add_lru+0x14a/0x1f0 mm/swap.c:511
 shmem_alloc_and_add_folio mm/shmem.c:1971 [inline]
 shmem_get_folio_gfp+0x7ab/0xd60 mm/shmem.c:2535
 shmem_get_folio mm/shmem.c:2641 [inline]
 shmem_write_begin+0xa8/0x190 mm/shmem.c:3291
 generic_perform_write+0x184/0x490 mm/filemap.c:4254
 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3466
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x52a/0x960 fs/read_write.c:686
 ksys_write+0xda/0x1a0 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:746
 x64_sys_call+0x2802/0x3000 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888119a6e0e8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 9528 Comm: syz.1.1531 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================
loop1: detected capacity change from 0 to 32768
 loop1: p1 p2 p3 < > p4 < p5 p6 >
loop1: p1 start 460800 is beyond EOD, truncated
loop1: p2 size 83886080 extends beyond EOD, truncated
loop1: p5 start 460800 is beyond EOD, truncated
loop1: p6 size 83886080 extends beyond EOD, truncated