EXT4-fs (loop4): 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 0xffff888237d26f50 of 8 bytes by task 3950 on cpu 1:
 bh_lru_install fs/buffer.c:1345 [inline]
 find_get_block_common+0x4f0/0x960 fs/buffer.c:1410
 __find_get_block_nonatomic fs/buffer.c:1429 [inline]
 bdev_getblk+0x83/0x3b0 fs/buffer.c:1453
 sb_getblk_gfp include/linux/buffer_head.h:392 [inline]
 __read_extent_tree_block+0xad/0x470 fs/ext4/extents.c:564
 ext4_ext_remove_space+0x1cc1/0x2900 fs/ext4/extents.c:3000
 ext4_ext_truncate+0xc7/0x170 fs/ext4/extents.c:4484
 ext4_truncate+0x70d/0xae0 fs/ext4/inode.c:4643
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x549/0x730 fs/ext4/inode.c:1486
 ext4_da_write_end+0x65/0x800 fs/ext4/inode.c:3277
 generic_perform_write+0x312/0x490 mm/filemap.c:4196
 ext4_buffered_write_iter+0x1ee/0x3c0 fs/ext4/file.c:299
 ext4_file_write_iter+0x383/0xf00 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x527/0x960 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/0x2ff0 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 0xffff888237d26f50 of 8 bytes by task 3304 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1551
 cpu_needs_drain mm/swap.c:787 [inline]
 __lru_add_drain_all+0x234/0x3f0 mm/swap.c:874
 lru_add_drain_all+0x10/0x20 mm/swap.c:890
 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:1766
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7395
 deactivate_locked_super+0x75/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1375
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1382
 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:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888107231c98

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3304 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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