Description
The kvm_arch_vcpu_ioctl_set_sregs function in the KVM in Linux kernel 2.6 before 2.6.30, when running on x86 systems, does not validate the page table root in a KVM_SET_SREGS call, which allows local users to cause a denial of service (crash or hang) via a crafted cr3 value, which triggers a NULL pointer dereference in the gfn_to_rmap function.
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 | kvm | 72+dfsg-5~lenny2 | DSA-1846-1 |
| Debian 5.0 | linux-2.6 | 2.6.26-17lenny1 | DSA-1845-1 |
Advisories 2
- DSA-1846-1 kvm - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-1845-1 linux-2.6 - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- 35675 third-party-advisory
- MDVSA-2010:198 vendor-advisory
- USN-807-1 vendor-advisory
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=59839dfff5eabca01cc4e20b45797a60a80af8cb
- http://sourceforge.net/tracker/?func=detail&atid=893831&aid=2687641&group_id=180599
- 36045 third-party-advisory
- 36054 third-party-advisory
- DSA-1845 vendor-advisory
- [oss-security] 20090630 CVE Request: kernel: kvm: failure to validate cr3 after KVM_SET_SREGS mailing-list
- http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git%3Ba=blob%3Bf=queue-2.6.30/kvm-x86-check-for-cr3-validity-in-ioctl_set_sregs.patch%3Bh=b48a47dad2cf76358b327368f80c0805e6370c68%3Bhb=e7c45b24f298b5d9efd7d401150f64a1b51aaac4