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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c26f58 of 8 bytes by task 12 on cpu 0:
 bh_lru_install fs/buffer.c:1345 [inline]
 find_get_block_common+0x50e/0x960 fs/buffer.c:1410
 __getblk_slow fs/buffer.c:-1 [inline]
 bdev_getblk+0x30d/0x3b0 fs/buffer.c:1461
 sb_getblk_gfp include/linux/buffer_head.h:392 [inline]
 ext4_ext_grow_indepth fs/ext4/extents.c:1335 [inline]
 ext4_ext_create_new_leaf fs/ext4/extents.c:1434 [inline]
 ext4_ext_insert_extent+0xa3d/0x29b0 fs/ext4/extents.c:2117
 ext4_split_extent_at+0x623/0x990 fs/ext4/extents.c:3255
 ext4_split_extent+0x1af/0x3b0 fs/ext4/extents.c:3406
 ext4_split_convert_extents fs/ext4/extents.c:3743 [inline]
 ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3915 [inline]
 ext4_ext_map_blocks+0xb58/0x38a0 fs/ext4/extents.c:4274
 ext4_map_create_blocks fs/ext4/inode.c:609 [inline]
 ext4_map_blocks+0x5ee/0xd00 fs/ext4/inode.c:811
 mpage_map_one_extent fs/ext4/inode.c:2374 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2468 [inline]
 ext4_do_writepages+0x15e1/0x2750 fs/ext4/inode.c:2931
 ext4_writepages+0x176/0x300 fs/ext4/inode.c:3025
 do_writepages+0x1c3/0x310 mm/page-writeback.c:2634
 __writeback_single_inode+0x80/0x7c0 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x48f/0xa30 fs/fs-writeback.c:1976
 wb_writeback+0x252/0x5c0 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x194/0x910 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x11f/0x1b0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c26f58 of 8 bytes by task 3299 on cpu 1:
 has_bh_in_lru+0x54/0x1f0 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+0xe3/0x210 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 -> 0xffff8881073196e8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3299 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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