Messages in this thread | | | Date | Mon, 19 Sep 2011 17:30:49 +0300 | Subject | Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo | From | Pekka Enberg <> |
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> On Wed, Sep 14, 2011 at 12:27 -0700, Kees Cook wrote: >> On Sat, Sep 10, 2011 at 08:41:34PM +0400, Vasiliy Kulikov wrote: >> > Historically /proc/slabinfo has 0444 permissions and is accessible to >> > the world. slabinfo contains rather private information related both to >> > the kernel and userspace tasks. Depending on the situation, it might >> > reveal either private information per se or information useful to make >> > another targeted attack. Some examples of what can be learned by >> > reading/watching for /proc/slabinfo entries: >> > ... >> > World readable slabinfo simplifies kernel developers' job of debugging >> > kernel bugs (e.g. memleaks), but I believe it does more harm than >> > benefits. For most users 0444 slabinfo is an unreasonable attack vector. >> > >> > Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
On Sun, Sep 18, 2011 at 8:05 PM, Vasiliy Kulikov <segoon@openwall.com> wrote: >> Haven't had any mass complaints about the 0400 in Ubuntu (sorry Dave!), so >> I'm obviously for it. >> >> Reviewed-by: Kees Cook <kees@ubuntu.com> > > Looks like the members of the previous slabinfo discussion don't object > against the patch now and it got two other Reviewed-by responses. Can > you merge it as-is or should I probably convince someone else?
We discussed this in March (google for 'Make /proc/slabinfo 0400') and concluded that it's not worth it doesn't really protect from anything and causes harm to developers.
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