[OE-core] [PATCH] classes/sanity: check for suid root command evility

[Mark Hatle]

On 7/26/13 5:48 AM, Paul Eggleton wrote:
> Some users have been found to have an unnamed third-party piece of
> software installed which sets chmod, chown and mknod as suid root as
> part of its installation process. This interferes with the operation of
> pseudo and can result in files really being owned by root within the
> build output, and therefore breaks the build, apart from being a
> security issue. Check for this and bail out early if it is found.
>
> Reported-by: Nicolas Dechesne <nicolas.dechesne at linaro.org>
>
> Signed-off-by: Paul Eggleton <paul.eggleton at linux.intel.com>

Should these items be added to the buildtools-tarball target?  It might help 
avoid the problem in the same way we already do to detect the bad make, tar, etc..

--Mark

> ---
>   meta/classes/sanity.bbclass | 10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/meta/classes/sanity.bbclass b/meta/classes/sanity.bbclass
> index a505a5d..0546293 100644
> --- a/meta/classes/sanity.bbclass
> +++ b/meta/classes/sanity.bbclass
> @@ -569,6 +569,16 @@ def check_sanity_everybuild(status, d):
>       if 0 == os.getuid():
>           raise_sanity_error("Do not use Bitbake as root.", d)
>
> +    # Some third-party software apparently relies on chmod etc. being suid root (!!)
> +    import stat
> +    suid_check_bins = "chown chmod mknod".split()
> +    for bin_cmd in suid_check_bins:
> +        bin_path = bb.utils.which(os.environ["PATH"], bin_cmd)
> +        if bin_path:
> +            bin_stat = os.stat(bin_path)
> +            if bin_stat.st_uid == 0 and bin_stat.st_mode & stat.S_ISUID:
> +                status.addresult('%s has the setuid bit set. This interferes with pseudo and may cause other issues that break the build process.\n' % bin_path)
> +
>       # Check the Python version, we now have a minimum of Python 2.7.3
>       import sys
>       if sys.hexversion < 0x020703F0:
>