syzbot

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BUG: KCSAN: data-race in delete_from_page_cache_batch / folio_mapping

write to 0xffffea00047d06d8 of 8 bytes by task 4940 on cpu 1:
 page_cache_delete_batch mm/filemap.c:310 [inline]
 delete_from_page_cache_batch+0x33c/0x750 mm/filemap.c:336
 truncate_inode_pages_range+0x1fe/0x7e0 mm/truncate.c:405
 truncate_inode_pages+0x24/0x30 mm/truncate.c:485
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x1ed/0x270 block/bdev.c:207
 sb_set_blocksize+0x93/0x170 block/bdev.c:240
 sb_min_blocksize+0x53/0x60 block/bdev.c:255
 ext4_load_super fs/ext4/super.c:5103 [inline]
 __ext4_fill_super fs/ext4/super.c:5324 [inline]
 ext4_fill_super+0x39e/0x37c0 fs/ext4/super.c:5793
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5825
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3760 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3836
 path_mount+0x4d0/0xbc0 fs/namespace.c:4146
 do_mount fs/namespace.c:4159 [inline]
 __do_sys_mount fs/namespace.c:4348 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4325
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4325
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 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

read to 0xffffea00047d06d8 of 8 bytes by task 3819 on cpu 0:
 folio_mapping+0xa1/0xe0 mm/util.c:703
 folio_evictable mm/internal.h:566 [inline]
 lru_add+0x8d/0x490 mm/swap.c:136
 folio_batch_move_lru+0x1c5/0x270 mm/swap.c:172
 lru_add_drain_cpu+0x66/0x210 mm/swap.c:648
 lru_add_drain mm/swap.c:737 [inline]
 __folio_batch_release+0x44/0xb0 mm/swap.c:1059
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x327/0xb10 mm/shmem.c:1149
 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
 end_renaming fs/namei.c:4096 [inline]
 filename_renameat2+0x493/0x6e0 fs/namei.c:6146
 __do_sys_rename fs/namei.c:6188 [inline]
 __se_sys_rename+0x4a/0x1c0 fs/namei.c:6184
 __x64_sys_rename+0x31/0x40 fs/namei.c:6184
 x64_sys_call+0x2b3/0x3020 arch/x86/include/generated/asm/syscalls_64.h:83
 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: 0xffff8881005f17e0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3819 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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