On Wed, Mar 2, 2022 at 12:07 PM Kees Cook [off-list ref] wrote:

I've long wanted to change kfree() to explicitly set pointers to NULL on
free. https://github.com/KSPP/linux/issues/87

We've had this discussion with the gcc people in the past, and gcc
actually has some support for it, but it's sadly tied to the actual
function name (ie gcc has some special-casing for "free()")

See

    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94527

for some of that discussion.

Oh, and I see some patch actually got merged since I looked there last
so that you can mark "deallocator" functions, but I think it's only
for the context matching, not for actually killing accesses to the
pointer afterwards.

               Linus