Messages in this thread | | | Date | Thu, 23 Nov 2017 11:47:52 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables |
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On Wed 2017-11-22 17:19:07, Pavel Machek wrote: > Hi! > > > KAISER makes it harder to defeat KASLR, but makes syscalls and > > interrupts slower. These patches are based on work from a team at > > Graz University of Technology posted here[1]. The major addition is > > support for Intel PCIDs which builds on top of Andy Lutomorski's PCID > > work merged for 4.14. PCIDs make KAISER's overhead very reasonable > > for a wide variety of use cases. > > Is it useful? > > > Full Description: > > > > KAISER is a countermeasure against attacks on kernel address > > information. There are at least three existing, published, > > approaches using the shared user/kernel mapping and hardware features > > to defeat KASLR. One approach referenced in the paper locates the > > kernel by observing differences in page fault timing between > > present-but-inaccessable kernel pages and non-present pages. > > I mean... evil userspace will still be able to determine kernel's > location using cache aliasing effects, right?
Issues with AnC attacks are tracked via several CVE identifiers.
CVE-2017-5925 is assigned to track the developments for Intel processors CVE-2017-5926 is assigned to track the developments for AMD processors
Pavel
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