Re: kern/53474: mmap get anon execuable memory return MAP_FAILED

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Thu, Jul 26, 2018 at 10:40:01PM +0000, ? ?? wrote:
> The following reply was made to PR kern/53474; it has been noted by GNATS.
> 
> From: ? ?? <zh_jq%outlook.com@localhost>
> To: "gnats-bugs%netbsd.org@localhost" <gnats-bugs%netbsd.org@localhost>
> Cc: Martin Husemann <martin%duskware.de@localhost>
> Subject: Re: kern/53474: mmap get anon execuable memory return MAP_FAILED
> Date: Thu, 26 Jul 2018 15:19:44 +0000
> 
>  Sorry, resend again, as the previous one has been changed by outlook.com
>  >  On Thu, Jul 26, 2018 at 02:15:00PM +0000, zh_jq%outlook.com@localhost wrote:
>  >  >         void *retval =3D mmap(NULL, 4096, PROT_READ | PROT_WRITE |
>  >  >         PROT_EXEC, MAP_PRIVATE | MAP_ANON, -1, 0);
>  >  You can not create writable + executable mappings when pax mprotect is
>  >  active (which is the default on many architectures). See mremap(2).
>  OK, got it.
>  I will write a bug report to pcre2.
>  As a temprate solution I will disable security.pax.mprotect.enabled.

pkgsrc/devel/libffi/patches/patch-src_closures.c illustrates a possible
fix.

Joerg