EXT4-fs (loop2): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237d26b30 of 8 bytes by task 8546 on cpu 1:
 bh_lru_install fs/buffer.c:1337 [inline]
 __find_get_block+0x430/0x8a0 fs/buffer.c:1400
 bdev_getblk+0x30/0x3b0 fs/buffer.c:1425
 __getblk include/linux/buffer_head.h:379 [inline]
 sb_getblk include/linux/buffer_head.h:385 [inline]
 __ext4_get_inode_loc+0x328/0x9a0 fs/ext4/inode.c:4454
 ext4_get_inode_loc fs/ext4/inode.c:4582 [inline]
 ext4_reserve_inode_write+0xd9/0x240 fs/ext4/inode.c:5860
 __ext4_mark_inode_dirty+0x92/0x440 fs/ext4/inode.c:6037
 ext4_dirty_inode+0x91/0xb0 fs/ext4/inode.c:6074
 __mark_inode_dirty+0x166/0x7e0 fs/fs-writeback.c:2527
 generic_update_time fs/inode.c:2064 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 __file_update_time fs/inode.c:2305 [inline]
 file_update_time+0x285/0x2b0 fs/inode.c:2335
 ext4_page_mkwrite+0x18c/0xb90 fs/ext4/inode.c:6192
 do_page_mkwrite mm/memory.c:3287 [inline]
 do_shared_fault mm/memory.c:5594 [inline]
 do_fault mm/memory.c:5656 [inline]
 do_pte_missing mm/memory.c:4160 [inline]
 handle_pte_fault mm/memory.c:5997 [inline]
 __handle_mm_fault mm/memory.c:6140 [inline]
 handle_mm_fault+0x14ba/0x2e80 mm/memory.c:6309
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x3b9/0x6a0 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237d26b30 of 8 bytes by task 3303 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1521
 smp_call_function_many_cond+0x30a/0xbc0 kernel/smp.c:838
 on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1052
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1530
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9b/0x1a0 block/bdev.c:674
 blkdev_put_whole block/bdev.c:681 [inline]
 bdev_release+0x2f9/0x420 block/bdev.c:1106
 blkdev_release+0x15/0x20 block/fops.c:660
 __fput+0x2ac/0x640 fs/file_table.c:465
 ____fput+0x1c/0x30 fs/file_table.c:493
 task_work_run+0x13c/0x1b0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 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+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888104fdd0d0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3303 Comm: syz-executor Not tainted 6.14.0-syzkaller-13389-ga52a3c18cdf3 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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