CVE-2024-46794 x86/tdx: Fix data leak in mmio_read()

2024-09-1807:12:49

Linux

www.cve.org

x86

tdx

data leak

mmio

tdvmcall

vmm

uninitialized variable

security vulnerability

linux kernel

EPSS

Percentile

16.4%

JSON

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

x86/tdx: Fix data leak in mmio_read()

The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an
address from the VMM.

Sean noticed that mmio_read() unintentionally exposes the value of an
initialized variable (val) on the stack to the VMM.

This variable is only needed as an output value. It did not need to be
passed to the VMM in the first place.

Do not send the original value of *val to the VMM.

[ dhansen: clarify what ‘val’ is used for. ]

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "arch/x86/coco/tdx/tdx.c"
    ],
    "versions": [
      {
        "version": "31d58c4e557d",
        "lessThan": "26c6af49d26f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "31d58c4e557d",
        "lessThan": "ef00818c50cf",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "31d58c4e557d",
        "lessThan": "b55ce742afcb",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "31d58c4e557d",
        "lessThan": "b6fb565a2d15",
        "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/coco/tdx/tdx.c"
    ],
    "versions": [
      {
        "version": "5.19",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.19",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.110",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.51",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.10",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]