Re: Hijacking malloc called within musl libc

[Rich Felker <dalias@libc.org>]

On Mon, Jun 03, 2019 at 02:46:01PM -0400, sva sva wrote:
> I am in fact using version 1.1.19 and don't have the option to upgrade to
> 1.1.20. My config.mak file also contains the option -Bsymbolic-functions in
> the LDFLAGS_AUTO variable.

1.1.20 was the first version that supported malloc interposition, and
some related bugs were fixed in the next 1 or 2 versions. Just
removing -Bsymbolic-functions is not sufficient to make it safe.

Rich


> On Fri, May 31, 2019 at 9:34 AM Rich Felker <dalias@libc.org> wrote:
> 
> > On Fri, May 31, 2019 at 01:43:17PM +0200, Szabolcs Nagy wrote:
> > > * sva sva <azharivs@gmail.com> [2019-05-31 00:13:27 -0400]:
> > > > I am interposing all malloc/calloc/realloc/free/memalign but still the
> > > > realloc in scandir gets called from musl's libc. Does that make sense?
> > >
> > > no.
> > >
> > > it works for me as expected.
> > >
> > > you need to write down what you did, what you expected and what you got
> > instead.
> > > (how did you verify that the musl internal realloc gets called?
> > > it can be a bug in your interposer, in your static linker, in ...)
> >
> > It's almost certainly a matter of using a pre-1.1.20 version of musl,
> > or having an old config.mak from pre-1.1.20 musl (with
> > -Bsymbolic-functions) rather than re-running configure with the
> > current version.