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