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CVE-2026-64183

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: efi: Allocate runtime workqueue before ACPI init Since commit 5894cf571e14 ("acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers") ACPI PRM calls are delegated to a workqueue which runs in a kernel thread, making it easier to detect and mitigate faulting memory accesses performed by the firmware. Rafael reports that such PRM accesses may occur before efisubsys_init() executes, which is where the workqueue is allocated, leading to NULL pointer dereferences. Since acpi_init() [which triggers the early PRM accesses] executes as a subsys_initcall() as well, and has its own dependencies that may be sensitive to initcall ordering, deferring acpi_init() is not an option. So instead, split off the workqueue allocation into its own postcore initcall, as this is the only missing piece to allow EFI runtime calls to be made. This ensures that EFI runtime call (including PRM calls) are accessible to all code running at subsys_initcall() level.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:18:00.703000
Last modified
2026-11-06 17:18:39.427000
View original CVE JSON 
{
  "id": "CVE-2026-64183",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-19T16:18:00.703",
  "lastModified": "2026-11-06T17:18:39.427",
  "vulnStatus": "Analyzed",
  "cveTags": [],
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    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nefi: Allocate runtime workqueue before ACPI init\n\nSince commit\n\n  5894cf571e14 (\"acpi/prmt: Use EFI runtime sandbox to invoke PRM handlers\")\n\nACPI PRM calls are delegated to a workqueue which runs in a kernel\nthread, making it easier to detect and mitigate faulting memory accesses\nperformed by the firmware.\n\nRafael reports that such PRM accesses may occur before efisubsys_init()\nexecutes, which is where the workqueue is allocated, leading to NULL\npointer dereferences. Since acpi_init() [which triggers the early PRM\naccesses] executes as a subsys_initcall() as well, and has its own\ndependencies that may be sensitive to initcall ordering, deferring\nacpi_init() is not an option.\n\nSo instead, split off the workqueue allocation into its own postcore\ninitcall, as this is the only missing piece to allow EFI runtime calls\nto be made. This ensures that EFI runtime call (including PRM calls) are\naccessible to all code running at subsys_initcall() level."
    }
  ],
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