CVE-2021-47604 vduse: check that offset is within bounds in get_config()

2024-06-1914:54:03

Linux

www.cve.org

linux kernel

vulnerability

resolved

vduse

offset bounds

get_config

out of bounds read

unsigned value

vhost_vdpa_config_validate

0.0004 Low

EPSS

Percentile

9.1%

JSON

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

vduse: check that offset is within bounds in get_config()

This condition checks “len” but it does not check “offset” and that
could result in an out of bounds read if “offset > dev->config_size”.
The problem is that since both variables are unsigned the
“dev->config_size - offset” subtraction would result in a very high
unsigned value.

I think these checks might not be necessary because “len” and “offset”
are supposed to already have been validated using the
vhost_vdpa_config_validate() function. But I do not know the code
perfectly, and I like to be safe.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/vdpa/vdpa_user/vduse_dev.c"
    ],
    "versions": [
      {
        "version": "c8a6153b6c59",
        "lessThan": "ebbbc5fea3f6",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "c8a6153b6c59",
        "lessThan": "dc1db0060c02",
        "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/vdpa/vdpa_user/vduse_dev.c"
    ],
    "versions": [
      {
        "version": "5.15",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.15",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.11",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]