CVE-2021-46937

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/dbgfs: fix &amp;#39;struct pid&amp;#39; leaks in &amp;#39;dbgfs_target_ids_write()&amp;#39;<br /> <br /> DAMON debugfs interface increases the reference counts of &amp;#39;struct pid&amp;#39;s<br /> for targets from the &amp;#39;target_ids&amp;#39; file write callback<br /> (&amp;#39;dbgfs_target_ids_write()&amp;#39;), but decreases the counts only in DAMON<br /> monitoring termination callback (&amp;#39;dbgfs_before_terminate()&amp;#39;).<br /> <br /> Therefore, when &amp;#39;target_ids&amp;#39; file is repeatedly written without DAMON<br /> monitoring start/termination, the reference count is not decreased and<br /> therefore memory for the &amp;#39;struct pid&amp;#39; cannot be freed. This commit<br /> fixes this issue by decreasing the reference counts when &amp;#39;target_ids&amp;#39; is<br /> written.