static int pmu_get(struct task_struct *target,
		      const struct user_regset *regset,
		      unsigned int pos, unsigned int count,
		      void *kbuf, void __user *ubuf)
{
	/* Build tests */
	BUILD_BUG_ON(TSO(siar) + sizeof(unsigned long) != TSO(sdar));
	BUILD_BUG_ON(TSO(sdar) + sizeof(unsigned long) != TSO(sier));
	BUILD_BUG_ON(TSO(sier) + sizeof(unsigned long) != TSO(mmcr2));
	BUILD_BUG_ON(TSO(mmcr2) + sizeof(unsigned long) != TSO(mmcr0));

	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
		return -ENODEV;

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
			&target->thread.siar, 0,
			5 * sizeof(unsigned long));
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.