==================================================================
BUG: KCSAN: data-race in __find_get_block / has_bh_in_lru

read-write to 0xffff888237c26b68 of 8 bytes by task 8712 on cpu 0:
 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:4466
 ext4_get_inode_loc fs/ext4/inode.c:4594 [inline]
 ext4_reserve_inode_write+0xd9/0x240 fs/ext4/inode.c:5872
 __ext4_mark_inode_dirty+0x92/0x440 fs/ext4/inode.c:6049
 ext4_dirty_inode+0x91/0xb0 fs/ext4/inode.c:6086
 __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+0x192/0xba0 fs/ext4/inode.c:6204
 do_page_mkwrite mm/memory.c:3256 [inline]
 do_shared_fault mm/memory.c:5490 [inline]
 do_fault mm/memory.c:5552 [inline]
 do_pte_missing mm/memory.c:4059 [inline]
 handle_pte_fault mm/memory.c:5893 [inline]
 __handle_mm_fault mm/memory.c:6036 [inline]
 handle_mm_fault+0x130c/0x2b30 mm/memory.c:6205
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff888237c26b68 of 8 bytes by task 4210 on cpu 1:
 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
 invalidate_bdev+0x42/0x70 block/bdev.c:100
 ext4_put_super+0x65b/0x910 fs/ext4/super.c:1343
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7393
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x26e/0x2e0 fs/namespace.c:1435
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1442
 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: 0xffff8881065d4f08 -> 0xffff888100742208

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4210 Comm: syz-executor Not tainted 6.14.0-syzkaller-10514-g7f2ff7b62617 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================