powerpc/perf: Fix crash in perfinstructionpointer() when ppmu is not set
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.12.13 by commit 74c3c34a04bc226f77b9e515aa067072cff44e52, it was introduced in version v5.11 by commit 2ca13a4cc56c920a6c9fc8ee45d02bccacd7f46c. For more details please see the references link.