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The controversial part of this patch is that I've changed it so we now prevent integer overflows for VME_USER types and before we didn't. I view it as kernel-hardening. I looked at a couple places that used VME_USER types and they seemed pretty suspicious so I'm pretty sure preventing overflows here is a good idea. The most common problem which this function is for cases like VME_A16 where we don't put an upper bound on "size" so you could have "size" set to U64_MAX and a valid vme_base would overflow the "vme_base + size" into the valid range as well. In the VME_A64 case, the integer overflow checking doesn't work because "U64_MAX + 1" has an integer overflow and it's just a complicated way of saying zero. That VME_A64 case is sort of interesting as well because there is a VME_A64_MAX define which is set to "U64_MAX + 1". The compiler will never let anyone use it since it can't be stored in a u64 variable... With my patch it's now limited to just U64_MAX. Anyway, I put one integer overflow check at the start of the function and deleted all existing checks. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Dmitry Kalinkin <dmitry.kalinkin@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.