title: mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()'
description: In the Linux kernel, the following vulnerability has been resolved:
mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()'
DAMON debugfs interface increases the reference counts of 'struct pid's
for targets from the 'target_ids' file write callback
('dbgfs_target_ids_write()'), but decreases the counts only in DAMON
monitoring termination callback ('dbgfs_before_terminate()').
Therefore, when 'target_ids' 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 'target_ids' is
written.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 4bc05954d007, lessThan: ffe4a1ba1a82, status: affected, versionType: git
version: 4bc05954d007, lessThan: ebb3f994dd92, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.15, status: affected
version: 0, lessThan: 5.15, status: unaffected, versionType: custom
version: 5.15.13, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 5.16, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
