Re: Adding a --preserve= option to install

[Sven Vermeulen]

I would definitely support this, but it has to remain flexible. We do not always want to copy all security.* attributes, sometimes this isn't even allowed.

For instance, security.ima and security.evm are managed primarily by the IMA/EVM subsystem in the Linux kernel. The SELinux attributes might not be allowed to be changed. Yet some other attributes might be better to install with them, like the POSIX ACLs.

Wkr,
  Sven Vermeulen

"Anthony G. Basile" <address@hidden> wrote:

Hi everyone,

I'm writing about an issue that came up in Gentoo wrt coreutil's install 
[1].  There we are working on moving PaX security markings [2] from our 
systems' ELF program headers to an extended attribute field named 
"user.pax.flags".  The advantage of leaving the markings in the ELF the 
way we had it is that they always travel with the executables/libraries, 
but the disadvantage is that it makes our ELF objects less in line with 
what you get on other linux distros with all the issues that come with that.

The problem we encountered is that for some packages, we need to do the 
xattr pax markings *before* running install in our package management 
system.  For example we need to mark python to run correctly under a 
kernel enforcing PaX.  But we need to mark it before running tests and 
therefore before
install.

The problem comes because coreutil's install does not have a --preserve= 
option like cp does.  It does have --preserve-context for SELinux but 
not a more general preserve option for extended attributes.  In many 
ways, xattr PaX markings follow the same design principles as SELinux 
security labels.

I'd like to propose adding a --preserve= to install.  Comments?


Ref.
[1] https://bugs.gentoo.org/show_bug.cgi?id=470660
[2] http://en.wikipedia.org/wiki/PaX

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