EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c26b78 of 8 bytes by task 31 on cpu 0:
 bh_lru_install fs/buffer.c:1348 [inline]
 find_get_block_common+0x50e/0x960 fs/buffer.c:1413
 __find_get_block_nonatomic fs/buffer.c:1432 [inline]
 bdev_getblk+0x7f/0x3d0 fs/buffer.c:1456
 __getblk include/linux/buffer_head.h:382 [inline]
 sb_getblk include/linux/buffer_head.h:388 [inline]
 __ext4_get_inode_loc+0x303/0x930 fs/ext4/inode.c:4455
 ext4_get_inode_loc fs/ext4/inode.c:4583 [inline]
 ext4_reserve_inode_write+0xdb/0x230 fs/ext4/inode.c:5889
 __ext4_mark_inode_dirty+0x8c/0x3f0 fs/ext4/inode.c:6066
 ext4_convert_unwritten_extents+0x1f5/0x2b0 fs/ext4/extents.c:4830
 ext4_convert_unwritten_io_end_vec+0xa1/0x110 fs/ext4/extents.c:4861
 ext4_end_io_end+0x74/0x240 fs/ext4/page-io.c:199
 ext4_do_flush_completed_IO fs/ext4/page-io.c:287 [inline]
 ext4_end_io_rsv_work+0x151/0x1e0 fs/ext4/page-io.c:302
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c26b78 of 8 bytes by task 3325 on cpu 1:
 has_bh_in_lru+0x54/0x1f0 fs/buffer.c:1554
 cpu_needs_drain mm/swap.c:780 [inline]
 __lru_add_drain_all+0x234/0x3f0 mm/swap.c:867
 lru_add_drain_all+0x10/0x20 mm/swap.c:883
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1343
 generic_shutdown_super+0xe3/0x210 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7393
 deactivate_locked_super+0x75/0x1c0 fs/super.c:473
 deactivate_super+0x97/0xa0 fs/super.c:506
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1431
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1438
 task_work_run+0x12e/0x1a0 kernel/task_work.c:227
 resume_user_mode_work+0x6a/0x70 include/linux/resume_user_mode.h:50
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x77/0xb0 kernel/entry/common.c:218
 do_syscall_64+0xdd/0x1a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888106f78478

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3325 Comm: syz-executor Not tainted 6.15.0-rc7-syzkaller-00014-gd608703fcdd9 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.