First published: Tue Jan 27 2015(Updated: )
It was found that the Linux kernel KVM subsystem's sysenter instruction emulation was not sufficient. An unprivileged guest user could use this flaw to escalate their privileges by tricking the hypervisor to emulate a SYSENTER instruction in 16-bit mode, if the guest OS does not initialize the SYSENTER MSRs. Please note that the Red Hat Enterprise Linux with KVM certified guest operating systems do initialize the SYSENTER MSRs and are thus not vulnerable to this issue when running on KVM hypervisor. References: <a href="http://www.openwall.com/lists/oss-security/2015/01/27/6">http://www.openwall.com/lists/oss-security/2015/01/27/6</a> Upstream patch: <a href="http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f3747379accba8e95d70cec0eae0582c8c182050">http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f3747379accba8e95d70cec0eae0582c8c182050</a> Acknowledgements: Red Hat would like to thank Nadav Amit for reporting this issue.
Credit: secalert@redhat.com secalert@redhat.com
Affected Software | Affected Version | How to fix |
---|---|---|
Linux Linux kernel | <3.18.5 | |
Canonical Ubuntu Linux | =12.04 | |
Canonical Ubuntu Linux | =14.04 | |
Canonical Ubuntu Linux | =14.10 | |
Debian Debian Linux | =7.0 | |
Debian Debian Linux | =8.0 | |
Oracle Linux | =5 | |
Oracle Linux | =7 | |
Redhat Enterprise Linux Desktop | =6.0 | |
Redhat Enterprise Linux Server | =6.0 | |
Redhat Enterprise Linux Workstation | =6.0 | |
debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.12.5-1 6.12.6-1 |
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