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vulnrichmentLinuxVULNRICHMENT:CVE-2021-47112
HistoryMar 15, 2024 - 8:14 p.m.

CVE-2021-47112 x86/kvm: Teardown PV features on boot CPU as well

2024-03-1520:14:20
Linux
github.com
cve-2021-47112
linux kernel
x86/kvm
teardown pv features
boot cpu
hypervisor
hibernation
memory
security vulnerability

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Various PV features (Async PF, PV EOI, steal time) work through memory
shared with hypervisor and when we restore from hibernation we must
properly teardown all these features to make sure hypervisor doesn’t
write to stale locations after we jump to the previously hibernated kernel
(which can try to place anything there). For secondary CPUs the job is
already done by kvm_cpu_down_prepare(), register syscore ops to do
the same for boot CPU.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/kernel/kvm.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "7620a669111b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "38b858da1c58",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "d1629b5b925d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "8b79feffeca2",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/kernel/kvm.c"
    ],
    "versions": [
      {
        "version": "5.4.125",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.43",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.10",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%