Re: Bug#1022787: libc6-dev: Lintian warns that all mips*el executables have executable stack

Hi,

On 2022-10-26 22:09, Aurelien Jarno wrote:
> control: tag -1 + moreinfo
> 
> Hi,
> 
> On 2022-10-25 21:07, Simon McVittie wrote:
> > Package: libc6-dev
> > Version: 2.35-4
> > Severity: normal
> > X-Debbugs-Cc: [email protected], [email protected], [email protected]
> > User: [email protected]
> > Usertags: mips mipsel
> > 
> > All mips*el executables and libraries appear to have an executable stack,
> > resulting in very large numbers of Lintian warnings, particularly for
> > packages with many small ELF objects like
> > <https://udd.debian.org/lintian/?packages=samba>.
> > 
> > Jessica Clarke looked into this and found that this is intentionally done
> > by glibc when targeting minimum kernel 4.8.0 or older with mips hardfloat:
> > https://github.com/bminor/glibc/blob/595c22ecd8e87a27fd19270ed30fdbae9ad25426/sysdeps/unix/sysv/linux/mips/configure.ac#L138-L143
> > 
> > Debian 9 had a kernel newer than 4.8.0, so I think Debian 12 probably
> > doesn't need to go that far into backwards compatibility? If the mips
> > porters agree, then glibc on mips*el should stop forcing an executable
> > stack, either by increasing the minimal kernel version or by patching
> > this out. That will provide some security hardening on mips*el.
> 
> Note that the other official architecture still have a kernel
> compatibility set to 3.2, so that will make a difference between
> architectures. There are discussions to increase it upstream, but this
> won't happened for bookworm. 
> 
> > Or, if the mips porters consider this backwards compatibility to be
> > more important than the security hardening of a non-executable stack,
> > then Lintian should stop issuing warnings about the executable stack on
> > mips*el to improve its signal/noise ratio.
> 
> At this stage there is nothing that can be done on the glibc side, the
> decision has to be taken by the mips porters.

We are getting very close to the toolchain freeze. Any decision about
that?

Regards
Aurelien