Re: [PATCH] selftests/mm: check strdup() and fix buf leak in parse_test_type()

Sounds good, no objection from me — happy to go with your version.

One small ask: since this fixes the issue from my original patch,
could you add a Reported-by: Anshuman Tewari
<[email protected]> when you post/apply it?

Thanks!

On Fri, 21 Aug 2026 at 21:48, David Hildenbrand (Arm) <[email protected]> wrote:
>
> On 8/21/26 18:09, Anshuman Tewari wrote:
> > Thanks David, agreed — strdup() is overkill here for a single-use
> > parse, and dropping it is the right call.
> >
> > One small consideration on the approach: working on argv[0] in place
> > means strsep() will overwrite the : separator with '\0', so the
> > original string (e.g. "khugepaged:anon") ends up truncated after
> > parsing. Nothing today reads argv[0] again afterward, so it's safe as
> > things stand, but it does mean correctness quietly depends on that
> > staying true — a future change that logs argv[0], re-parses it, or
> > echoes it back in an error/usage message would get the mutated version
> > instead of what the user actually typed.
> >
> > If we'd rather not rely on that invariant, an alternative that still
> > avoids strdup()/free() entirely: copy the type argument into a small
> > fixed-size stack buffer (with a bounds check against its length first)
> > and run strsep() on that copy instead of on argv[0] directly. Same
> > benefit as your version — no allocation, nothing to free, no
> > NULL-check needed — but argv[0] itself stays untouched.
> >
> > Happy to write this up as a v2 if it seems worthwhile, or if you think
> > relying on "nothing downstream needs argv[0]" is fine as-is, I'm okay
> > going with your version too. Your call.
>
> I don't think we have to worry about other such argv[0] users. If they ever
> appear, basic testing would reveal them.
>
> --
> Cheers,
>
> David