CVE-2021-47407 KVM: x86: Handle SRCU initialization failure during page track init

2024-05-2115:03:59

Linux

www.cve.org

cve-2021-47407

kvm

x86

linux kernel

vulnerability

srcu initialization

page track init

oom

null pointer deref

syzkaller

6.4 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.5%

JSON

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

KVM: x86: Handle SRCU initialization failure during page track init

Check the return of init_srcu_struct(), which can fail due to OOM, when
initializing the page track mechanism. Lack of checking leads to a NULL
pointer deref found by a modified syzkaller.

[Move the call towards the beginning of kvm_arch_init_vm. - Paolo]

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/include/asm/kvm_page_track.h",
      "arch/x86/kvm/mmu/page_track.c",
      "arch/x86/kvm/x86.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "deb294941767",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "4664318f73e4",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "eb7511bf9182",
        "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/include/asm/kvm_page_track.h",
      "arch/x86/kvm/mmu/page_track.c",
      "arch/x86/kvm/x86.c"
    ],
    "versions": [
      {
        "version": "5.10.71",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.14.10",
        "lessThanOrEqual": "5.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]