CVE-2021-46967 vhost-vdpa: fix vm_flags for virtqueue doorbell mapping

2024-02-2718:47:04

Linux

github.com

linux kernel

vhost-vdpa

virtqueue doorbell

vm_flags

iotlb

page structure

cve-2021-46967

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.7%

JSON

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

vhost-vdpa: fix vm_flags for virtqueue doorbell mapping

The virtqueue doorbell is usually implemented via registeres but we
don’t provide the necessary vma->flags like VM_PFNMAP. This may cause
several issues e.g when userspace tries to map the doorbell via vhost
IOTLB, kernel may panic due to the page is not backed by page
structure. This patch fixes this by setting the necessary
vm_flags. With this patch, try to map doorbell via IOTLB will fail
with bad address.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/vhost/vdpa.c"
    ],
    "versions": [
      {
        "version": "ddd89d0a059d",
        "lessThan": "3b8b6399666a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ddd89d0a059d",
        "lessThan": "940230a5c31e",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ddd89d0a059d",
        "lessThan": "93dbbf20e3ff",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "ddd89d0a059d",
        "lessThan": "3a3e0fad16d4",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/vhost/vdpa.c"
    ],
    "versions": [
      {
        "version": "5.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.8",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.36",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.11.20",
        "lessThanOrEqual": "5.11.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.3",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]