CVE-2025-21811

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> nilfs2: protect access to buffers with no active references<br /> <br /> nilfs_lookup_dirty_data_buffers(), which iterates through the buffers<br /> attached to dirty data folios/pages, accesses the attached buffers without<br /> locking the folios/pages.<br /> <br /> For data cache, nilfs_clear_folio_dirty() may be called asynchronously<br /> when the file system degenerates to read only, so<br /> nilfs_lookup_dirty_data_buffers() still has the potential to cause use<br /> after free issues when buffers lose the protection of their dirty state<br /> midway due to this asynchronous clearing and are unintentionally freed by<br /> try_to_free_buffers().<br /> <br /> Eliminate this race issue by adjusting the lock section in this function.