syzbot

EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / folio_mapping

write to 0xffffea000464f4d8 of 8 bytes by task 3765 on cpu 1:
 page_cache_delete_batch mm/filemap.c:306 [inline]
 delete_from_page_cache_batch+0x2f6/0x6f0 mm/filemap.c:332
 truncate_inode_pages_range+0x1b8/0x690 mm/truncate.c:380
 truncate_inode_pages+0x24/0x30 mm/truncate.c:460
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x259/0x310 block/bdev.c:207
 sb_set_blocksize+0x7a/0x100 block/bdev.c:224
 ext4_load_super fs/ext4/super.c:5110 [inline]
 __ext4_fill_super fs/ext4/super.c:5262 [inline]
 ext4_fill_super+0x12ab/0x34e0 fs/ext4/super.c:5724
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1679
 get_tree_bdev+0x1f/0x30 fs/super.c:1702
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5756
 vfs_get_tree+0x54/0x1d0 fs/super.c:1802
 do_new_mount+0x207/0x680 fs/namespace.c:3885
 path_mount+0x4a4/0xb20 fs/namespace.c:4209
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4410
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4410
 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166
 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 0xffffea000464f4d8 of 8 bytes by task 3314 on cpu 0:
 folio_mapping+0xa1/0x120 mm/util.c:701
 folio_evictable mm/internal.h:478 [inline]
 lru_add+0x80/0x430 mm/swap.c:136
 folio_batch_move_lru+0x177/0x230 mm/swap.c:168
 lru_add_drain_cpu+0x77/0x250 mm/swap.c:642
 lru_add_drain mm/swap.c:730 [inline]
 __folio_batch_release+0x44/0xb0 mm/swap.c:1049
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x22a/0x690 mm/truncate.c:383
 truncate_inode_pages mm/truncate.c:460 [inline]
 truncate_inode_pages_final+0x55/0x60 mm/truncate.c:495
 ext4_evict_inode+0xb2/0xd80 fs/ext4/inode.c:185
 evict+0x2e3/0x550 fs/inode.c:810
 iput_final fs/inode.c:1898 [inline]
 iput+0x447/0x5b0 fs/inode.c:1924
 ext4_mb_release+0x539/0x720 fs/ext4/mballoc.c:3817
 ext4_put_super+0x25c/0x7d0 fs/ext4/super.c:1307
 generic_shutdown_super+0xe3/0x210 fs/super.c:643
 kill_block_super+0x2a/0x70 fs/super.c:1753
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7391
 deactivate_locked_super+0x75/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1417
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1424
 task_work_run+0x12e/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe4/0x100 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888100631e18 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3314 Comm: syz-executor Not tainted 6.15.0-syzkaller-13804-g939f15e640f1 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================