CVE-2026-64059

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfs: Fix folio-&gt;private handling in netfs_perform_write()<br /> <br /> Under some circumstances, netfs_perform_write() doesn&amp;#39;t correctly<br /> manipulate folio-&gt;private between NULL, NETFS_FOLIO_COPY_TO_CACHE, pointing<br /> to a group and pointing to a netfs_folio struct, leading to potential<br /> multiple attachments of private data with associated folio ref leaks and<br /> also leaks of netfs_folio structs or netfs_group refs.<br /> <br /> Fix this by consolidating the place at which a folio is marked uptodate in<br /> one place and having that look at what&amp;#39;s attached to folio-&gt;private and<br /> decide how to clean it up and then set the new group. Also, the content<br /> shouldn&amp;#39;t be flushed if group is NULL, even if a group is specified in the<br /> netfs_group parameter, as that would be the case for a new folio. A<br /> filesystem should always specify netfs_group or never specify netfs_group.<br /> <br /> The Sashiko auto-review tool noted that it was theoretically possible that<br /> the fpos &gt;= ctx-&gt;zero_point section might leak if it modified a streaming<br /> write folio. This is unlikely, but with a network filesystem, third party<br /> changes can happen. It also pointed out that __netfs_set_group() would<br /> leak if called multiple times on the same folio from the "whole folio<br /> modify section".