This is only true from the point of view of the hardware. Linux like every Unix like is programmed is C, so this is _not_ true on targets when the representation of a NULL pointer is zero, which is the case for, oh well, just every target Linux and GCC supports...
Even after the compiler is instructed that NULL is less special than it thought and every single line of Linux is reviewed for this kind of problem, NULL pointers will stay special in the eye of third party tools. That's why it was a very very very bad idea at first to allow to map a page at address zero, and I guess if this "feature" stays there will again be security issues in the future because of that. So it's still a very bad idea, even if less very bad know that at least (some) people are conscious of one more thing they have to worry about when they write or review some Linux code.
Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds