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Re: CVE Request: Linux x86_64 NT flag issue - Linux kernel


From: cve-assign () mitre org
Date: Mon, 24 Aug 2015 23:21:15 -0400 (EDT)

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When I fixed Linux's NT flag handling, I added an optimization to
Linux 3.19 and up. A malicious 32-bit program might be able to leak
NT into an unrelated task. On a CONFIG_PREEMPT=y kernel, this is a
straightforward DoS. On a CONFIG_PREEMPT=n kernel, it's probably
still exploitable for DoS with some more care.

I believe that this could be used for privilege escalation, too, but
it won't be easy.

The fix is just to revert the optimization:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=512255a2ad2c832ca7d4de9f31245f73781922d0

Mitigation: CONFIG_IA32_EMULATION=n

Use CVE-2015-6666.

- -- 
CVE assignment team, MITRE CVE Numbering Authority
M/S M300
202 Burlington Road, Bedford, MA 01730 USA
[ PGP key available through http://cve.mitre.org/cve/request_id.html ]
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