On Wed, May 9, 2018 at 1:02 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > This is a stab at providing three new helpers for allocation size > calculation: > > struct_size(), array_size(), and array3_size(). > > These are implemented on top of Rasmus's overflow checking functions. The > existing allocators are adjusted to use the more efficient overflow > checks as well. > > I have left out the 8 tree-wide conversion patches of open-coded > multiplications into the new helpers, as those are largely > unchanged from v1. Everything can be seen here, though: > https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=kspp/overflow/array_size > > The question remains for what to do with the *calloc() and *_array*() > API. They could be entirely removed in favor of using the new helpers: > > kcalloc(n, size, gfp) -> kzalloc(array_size(n, size), gfp) > kmalloc_array(n, size, gfp) -> kmalloc(array_size(n, size), gfp) > > Changes from v1: > - use explicit overflow helpers instead of array_size() helpers. > - drop early-checks for SIZE_MAX. > - protect devm_kmalloc()-family from addition overflow. > - added missing overflow.h includes. > - fixed 0-day issues in a few treewide manual conversions I've added an allocation overflow addition to lib/test_overflow now, so I'll send a v3 soon. Does anyone want to provide an Ack or Reviewed for these? Also, any thoughts on *calloc() and *_array*() removal? -Kees -- Kees Cook Pixel Security
