malloc/calloc return value NULL check

[Thomas Stüfe]

Absolutely, yes.

The larger the allocated size, the more important. Linux kernel, by
default, only protects a small area against NULL accesses; depending on
distro, 4KB or 64 (?) KB. And the JVM, at various places, allocates in
low-area ranges. So accessing NULL+<large offset> can actually land you at
a valid unrelated address instead of faulting.

/Thomas

On Fri, Jul 11, 2025 at 2:57 PM Baesken, Matthias <matthias.baesken at sap.com>
wrote:

> Hi, when playing around with the  GCC static analyzer  (
> https://developers.redhat.com/articles/2022/04/12/state-static-analysis-gcc-12-compiler
> )   I noticed
>
> a lot of complaints about  missing  NULL checks of  malloc/calloc  return
> values in the code base.
>
>
>
> While we check these return values for NULL at a lot of places in the
> codebase,  it is not done always.
>
> Should we do it always  (except 3rd party code probably where we do not
> want to have large diffs to upstream) ?
>
>
>
> Or is it considered not important enough  to do it always?
>
>
>
> Best regards, Matthias
>
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