Bug 986295 (CVE-2013-2212)
| Summary: | CVE-2013-2212 kernel: xen: Excessive time to disable caching with HVM guests with PCI passthrough | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | Petr Matousek <pmatouse> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED NOTABUG | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | drjones, imammedo, pbonzini, rkrcmar, security-response-team |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2013-07-24 12:11:00 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 987914 | ||
| Bug Blocks: | 986297 | ||
Statement: Not vulnerable. This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5. This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as we did not have support for Xen hypervisor. Now public via: http://seclists.org/oss-sec/2013/q3/182 Created xen tracking bugs for this issue: Affects: fedora-all [bug 987914] |
HVM guests are able to manipulate their physical address space such that processing a subsequent request by that guest to disable caches takes an extended amount of time changing the cachability of the memory pages assigned to this guest. This applies only when the guest has been granted access to some memory mapped I/O region (typically by way of assigning a passthrough PCI device). This can cause the CPU which processes the request to become unavailable, possibly causing the hypervisor or a guest kernel (including the domain 0 one) to halt itself ("panic"). A malicious domain, given access to a device with memory mapped I/O regions, can cause the host to become unresponsive for a period of time, potentially leading to a DoS affecting the whole system. Only systems using the Intel variant of Hardware Assisted Paging (aka EPT) are vulnerable. Acknowledgements: Red Hat would like to thank the Xen for reporting this issue. Upstream acknowledges Zhenzhong Duan as the original reporter.