CVE-2021-46908 bpf: Use correct permission flag for mixed signed bounds arithmetic

2024-02-2706:53:49

Linux

github.com

cve-2021-46908

bpf

mixed signed bounds arithmetic

permission flag

spectre v1 masking mitigation

AI Score

6.9

Confidence

Low

EPSS

Percentile

5.1%

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

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

bpf: Use correct permission flag for mixed signed bounds arithmetic

We forbid adding unknown scalars with mixed signed bounds due to the
spectre v1 masking mitigation. Hence this also needs bypass_spec_v1
flag instead of allow_ptr_leaks.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2c78ee898d8f",
        "lessThan": "4f3ff11204ea",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2c78ee898d8f",
        "lessThan": "4ccdc6c6cae3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2c78ee898d8f",
        "lessThan": "960114839252",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "kernel/bpf/verifier.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.8"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.8",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "5.10.32",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.11.16",
        "versionType": "custom",
        "lessThanOrEqual": "5.11.*"
      },
      {
        "status": "unaffected",
        "version": "5.12",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "kernel/bpf/verifier.c"
    ],
    "defaultStatus": "affected"
  }
]