Description
The vmx_set_msr function in arch/x86/kvm/vmx.c in the VMX implementation in the KVM subsystem in the Linux kernel before 2.6.29.1 on the i386 platform allows guest OS users to cause a denial of service (OOPS) by setting the EFER_LME (aka "Long mode enable") bit in the Extended Feature Enable Register (EFER) model-specific register, which is specific to the x86_64 platform.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 5.0 | linux-2.6 | 2.6.26-15lenny2 | DSA-1800-1 |
| Debian 5.0 | user-mode-linux | 2.6.26-1um-2+15lenny2 | DSA-1800-1 |
| Debian 4.0 | linux-2.6.24 | 2.6.24-6~etchnhalf.8etch1 | DSA-1787-1 |
Advisories 2
- DSA-1787-1 linux-2.6.24 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1800-1 linux-2.6 user-mode-linux - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://www.kernel.org/pub/linux/kernel/v2.6/snapshots/patch-2.6.29-git1.log
- http://www.globalsecuritymag.com/Vigil-nce-Linux-kernel-denial-of%2C20090402%2C8311
- linux-kernel-eferlme-dos(49594) vdb-entry
- 35226 third-party-advisory
- http://patchwork.kernel.org/patch/15549/
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.29.1
- 34478 third-party-advisory
- 34331 vdb-entry
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=16175a796d061833aacfbd9672235f2d2725df65
- FEDORA-2009-5356 vendor-advisory
- SUSE-SA:2009:032 vendor-advisory
- 35656 third-party-advisory
- 20090516 rPSA-2009-0084-1 kernel mailing-list
- http://vigilance.fr/vulnerability/Linux-kernel-denial-of-service-via-EFER-8585
- 35120 third-party-advisory
- SUSE-SA:2009:031 vendor-advisory
- USN-793-1 vendor-advisory
- 34981 third-party-advisory
- DSA-1800 vendor-advisory
- 35387 third-party-advisory
- DSA-1787 vendor-advisory
- http://wiki.rpath.com/Advisories:rPSA-2009-0084
- [oss-security] 20090401 CVE request: kernel: KVM: VMX: Dont allow uninhibited access to EFER on i386 mailing-list
- 35121 third-party-advisory
- ADV-2009-0924 vdb-entry
- https://bugzilla.redhat.com/show_bug.cgi?id=502109
- 35394 third-party-advisory