When using the attribute "packed" on a bit-field, or on a struct containing a bit-field, the compiler will pick the smallest container size possible to store the bit-field, overriding the EABI requirement that the container type will be the same as the declared type. This bug causes the compiler to try to use the declared type anyway when the packed bit-field is also volatile, or if the containing struct is volatile. This would cause a memory access beyond the size of the actual container, and could result in a memory access beyond the bounds of defined memory.