|| ||Sebastian Krahmer <krahmer-l3A5Bk7waGM-AT-public.gmane.org> |
|| ||oss-security-ZwoEplunGu1jrUoiu81ncdBPR1lH4CV8-AT-public.gmane.org |
|| ||CLONE_NEWUSER|CLONE_FS root exploit |
|| ||Wed, 13 Mar 2013 16:39:56 +0100|
|| ||Article, Thread
Seems like CLONE_NEWUSER|CLONE_FS might be a forbidden
During evaluating the new user namespace thingie, it turned out
that its trivially exploitable to get a (real) uid 0,
as demonstrated here:
The trick is to setup a chroot in your CLONE_NEWUSER,
but also affecting the parent, which is running
in the init_user_ns, but with the chroot shared.
Then its trivial to get a rootshell from that.
Tested on a openSUSE12.1 with a custom build 3.8.2 (x86_64).
I hope I didnt make anything wrong, mixing up the UIDs,
or disabled important checks during kernel build on my test
~ perl self.pl
~ krahmer-l3A5Bk7waGM@public.gmane.org - SuSE Security Team
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