EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c26f28 of 8 bytes by task 11520 on cpu 0:
 bh_lru_install fs/buffer.c:1351 [inline]
 find_get_block_common+0x542/0x960 fs/buffer.c:1416
 __find_get_block_nonatomic fs/buffer.c:1435 [inline]
 bdev_getblk+0x83/0x3d0 fs/buffer.c:1459
 __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:4797
 ext4_get_inode_loc fs/ext4/inode.c:4925 [inline]
 ext4_reserve_inode_write+0xd7/0x250 fs/ext4/inode.c:6244
 __ext4_mark_inode_dirty+0x8c/0x3f0 fs/ext4/inode.c:6422
 ext4_truncate+0x8d3/0xad0 fs/ext4/inode.c:4597
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x44b/0x730 fs/ext4/inode.c:1465
 generic_perform_write+0x312/0x490 mm/filemap.c:4124
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_dio_write_iter fs/ext4/file.c:613 [inline]
 ext4_file_write_iter+0xdbf/0xf00 fs/ext4/file.c:721
 do_iter_readv_writev+0x3ee/0x4b0 fs/read_write.c:-1
 vfs_writev+0x2df/0x8b0 fs/read_write.c:1057
 do_pwritev fs/read_write.c:1153 [inline]
 __do_sys_pwritev2 fs/read_write.c:1211 [inline]
 __se_sys_pwritev2+0xfc/0x1c0 fs/read_write.c:1202
 __x64_sys_pwritev2+0x67/0x80 fs/read_write.c:1202
 x64_sys_call+0x1cea/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:329
 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 0xffff888237c26f28 of 8 bytes by task 4414 on cpu 1:
 has_bh_in_lru+0x8c/0x1f0 fs/buffer.c:1557
 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:1339
 generic_shutdown_super+0xe6/0x210 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: 0x0000000000000000 -> 0xffff88811a500dd0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4414 Comm: syz-executor Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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