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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 26037 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 11113 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_part block/bdev.c:774 [inline]
 bdev_release+0x292/0x420 block/bdev.c:1104
 blkdev_release+0x15/0x20 block/fops.c:660
 __fput+0x2ac/0x640 fs/file_table.c:465
 fput_close_sync+0xc0/0x110 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x55/0xe0 fs/open.c:1566
 x64_sys_call+0x262b/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff888106494410

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 11113 Comm: udevd Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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