CVE-2024-27437 vfio/pci: Disable auto-enable of exclusive INTx IRQ

2024-04-0508:24:44

Linux

github.com

linux kernel

vfio/pci

irqf_no_autoen

vulnerability

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.2%

JSON

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

vfio/pci: Disable auto-enable of exclusive INTx IRQ

Currently for devices requiring masking at the irqchip for INTx, ie.
devices without DisINTx support, the IRQ is enabled in request_irq()
and subsequently disabled as necessary to align with the masked status
flag. This presents a window where the interrupt could fire between
these events, resulting in the IRQ incrementing the disable depth twice.
This would be unrecoverable for a user since the masked flag prevents
nested enables through vfio.

Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
is never auto-enabled, then unmask as required.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "26389925d6c2",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "561d5e1998d5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "b7a2f0955ffc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "139dfcc4d723",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "2a4a666c4510",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "3b3491ad0f80",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "bf0bc84a20e6",
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      },
      {
        "status": "affected",
        "version": "89e1f7d4c66d",
        "lessThan": "fe9a7082684e",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/vfio/pci/vfio_pci_intrs.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.6"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.6",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "5.4.274",
        "versionType": "custom",
        "lessThanOrEqual": "5.4.*"
      },
      {
        "status": "unaffected",
        "version": "5.10.215",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.154",
        "versionType": "custom",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.84",
        "versionType": "custom",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.24",
        "versionType": "custom",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.7.12",
        "versionType": "custom",
        "lessThanOrEqual": "6.7.*"
      },
      {
        "status": "unaffected",
        "version": "6.8.3",
        "versionType": "custom",
        "lessThanOrEqual": "6.8.*"
      },
      {
        "status": "unaffected",
        "version": "6.9",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/vfio/pci/vfio_pci_intrs.c"
    ],
    "defaultStatus": "affected"
  }
]