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USB MSC library - null pointers

Question asked by Stefano Zanotti on Jul 11, 2016
Latest reply on Jul 14, 2016 by Stefano Zanotti
In the file "usbh_msc.c" generated by CubeMX there seem to be various instances of null pointer dereferencing.

Many functions begin with this statement:
MSC_HandleTypeDef *MSC_Handle =  (MSC_HandleTypeDef *) phost->pActiveClass->pData;

which doesn't check whether pActiveClass is NULL.

It seems that in some places the issue is quite harmless since there are other guards, like
if(phost->gState == HOST_CLASS)
in USBH_MSC_IsReady()
Nevertheless, in other places the problem is there, and it exists even when harmless (e.g. if you catch null pointer dereferencing by MPU-disabling access to the address 0x00000000.)

Is this a bug, or should the user code manually check for something, before calling functions like USBH_MSC_IsReady()?
What are those checks?