Mailinglist Archive: opensuse-packaging (68 mails)

[Marcus Meissner <meissner@xxxxxxx>]

Hi,

darix asked me to post this ;)

Quite some time ago we had the discussion how the
buildroot should be created in a secure way in %install.

BAD:
	%install
	rm -rf $RPM_BUILD_ROOT
	mkdir -p $RPM_BUILD_ROOT/usr/...  or make install

Why?

RPM_BUILD_ROOT is within /var/tmp and you just opened a trivial
race condition to a local attacker on your machine to take over
your account (or event root if you build as root).

It is better not to "rm -rf $RPM_BUILD_ROOT" in %install at all
(and rely on %clean to do it).

If you want to clean it, better do:
	%install
        rm -rf $RPM_BUILD_ROOT
        mkdir $RPM_BUILD_ROOT
	mkdir -p $RPM_BUILD_ROOT/usr ... or make install

In this case the "mkdir $RPM_BUILD_ROOT" would fail and the build would
abort if an attacker tries to replace the buildroot by his own symlink.

(or similar ;)

Ciao, Marcus
-- 
Working, but not speaking for the following german company:
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)
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