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On 11/06/2011 06:19 PM, Kevin Chadwick wrote: |
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> I've been using OpenBSD for a while now which has priv dropping X and |
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> the machdep.allowaperture=[0|1|2]. Theo has said firefox also |
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> annoyingly uses it's own memory management. |
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Hi, I've run many an OpenBSD boxes in my time. |
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Regarding Xorg. We do not drop privileges, that might be a good idea. |
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However, our X runs with almost full privileges. All toolchain |
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hardening is on except bind now. On the kernel side, X will run with |
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all hardening with the possible exception of CONFIG_GRKERNSEC_IO. If |
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you can run RBAC, it will help protect against rogue processes trying to |
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do iopl/ioperm calls. |
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As for firefox, I think Theo is referring to its built in malloc (I |
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forget what its called). I remember it causing problems, but not the |
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details. It may be related to its JIT which needs MPROTECT turned off |
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to run properly. |
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|
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> |
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> I have a few questions about Grsec that I'd love some input on as I am |
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> struggling to find the answers to them at the moment. |
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> |
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> I've read on the Gentoo-hardened archive and grsec config help that the |
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> iopl and ioperm should be protected with rbac if priviledged I/O is |
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> allowed. |
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> |
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> So you can disable the RAW_IO capability to all and sacrifice xrestarts. |
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> But if X already has all priviledges then I guess your just adding a |
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> hurdle which is made a bit higher with grsec, so obfuscation really |
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> and not complete security. Is there anything else you can do or is that |
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> what is meant by "You should use RBAC if you allow priviledged I/O"? |
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I would try running it with CONFIG_GRKERNSEC_IO set and see if it works. |
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Try nvidia with nouveau driver, if you have that. My guess is |
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proprietary drivers are going to get you in trouble here, so if you have |
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an ATI, you may have no choice in the matter. |
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|
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> |
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> The gentoo-handbook says something like the question of selinux|rbac| |
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> rsbac is a controversial one. It seems rsbac is the most secure but |
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> more difficult to use and has less starter policies around. Gentoo |
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> seems to have selinux policies. Does selinux have any more to offer than |
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> rbac for protecting X? |
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Its recommended that with workstations you run SELinux in targeted mode, |
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not strict. So, while it might offer something more for X (and I'm not |
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sure it does), this means loosening other restrictions that RBAC would |
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give you on a workstation. |
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|
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> |
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> Does CONFIG_PAX_MPROTECT_COMPAT have any effect on firefox and did |
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> mozilla refuse to patch their sources with the if !jit patch? |
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> |
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> Thanks |
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> |
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> Kc |
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-- |
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Anthony G. Basile, Ph.D. |
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Gentoo Linux Developer [Hardened] |
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E-Mail : blueness@g.o |
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GnuPG FP : 8040 5A4D 8709 21B1 1A88 33CE 979C AF40 D045 5535 |
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GnuPG ID : D0455535 |
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