In the Linux kernel, the following vulnerability has been resolved: regulator: tps6594: Fix device node reference leaks in multiphase loop

In the Linux kernel, the following vulnerability has been resolved:

regulator: tps6594: Fix device node reference leaks in multiphase loop

In tps6594_regulator_probe(), the multi-phase configuration loop calls
of_find_node_by_name() to find buck nodes by name, and of_get_parent()
twice to navigate to the PMIC parent node. None of the acquired node
references (np, intermediate parent, np_pmic_parent) are ever released
via of_node_put(), causing a reference leak on every loop iteration.

Additionally, of_find_node_by_name() can return NULL, but the result was
immediately passed to of_node_full_name() and of_get_parent() without a
NULL check, which could lead to a NULL pointer dereference.

Fix this by:

• Adding a NULL check for np after of_find_node_by_name()
• Storing the intermediate parent node in a local variable np_parent
• Calling of_node_put() on np, np_parent and np_pmic_parent at the
  end of each loop iteration