GHSA-C9QP-46J7-6QFJ

Vulnerability from github – Published: 2025-09-05 18:31 – Updated: 2026-10-15 03:34
VLAI
Details

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

crypto: qat - flush misc workqueue during device shutdown

Repeated loading and unloading of a device specific QAT driver, for example qat_4xxx, in a tight loop can lead to a crash due to a use-after-free scenario. This occurs when a power management (PM) interrupt triggers just before the device-specific driver (e.g., qat_4xxx.ko) is unloaded, while the core driver (intel_qat.ko) remains loaded.

Since the driver uses a shared workqueue (qat_misc_wq) across all devices and owned by intel_qat.ko, a deferred routine from the device-specific driver may still be pending in the queue. If this routine executes after the driver is unloaded, it can dereference freed memory, resulting in a page fault and kernel crash like the following:

BUG: unable to handle page fault for address: ffa000002e50a01c
#PF: supervisor read access in kernel mode
RIP: 0010:pm_bh_handler+0x1d2/0x250 [intel_qat]
Call Trace:
  pm_bh_handler+0x1d2/0x250 [intel_qat]
  process_one_work+0x171/0x340
  worker_thread+0x277/0x3a0
  kthread+0xf0/0x120
  ret_from_fork+0x2d/0x50

To prevent this, flush the misc workqueue during device shutdown to ensure that all pending work items are completed before the driver is unloaded.

Note: This approach may slightly increase shutdown latency if the workqueue contains jobs from other devices, but it ensures correctness and stability.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2025-39721"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-09-05T18:15:49Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: qat - flush misc workqueue during device shutdown\n\nRepeated loading and unloading of a device specific QAT driver, for\nexample qat_4xxx, in a tight loop can lead to a crash due to a\nuse-after-free scenario. This occurs when a power management (PM)\ninterrupt triggers just before the device-specific driver (e.g.,\nqat_4xxx.ko) is unloaded, while the core driver (intel_qat.ko) remains\nloaded.\n\nSince the driver uses a shared workqueue (`qat_misc_wq`) across all\ndevices and owned by intel_qat.ko, a deferred routine from the\ndevice-specific driver may still be pending in the queue. If this\nroutine executes after the driver is unloaded, it can dereference freed\nmemory, resulting in a page fault and kernel crash like the following:\n\n    BUG: unable to handle page fault for address: ffa000002e50a01c\n    #PF: supervisor read access in kernel mode\n    RIP: 0010:pm_bh_handler+0x1d2/0x250 [intel_qat]\n    Call Trace:\n      pm_bh_handler+0x1d2/0x250 [intel_qat]\n      process_one_work+0x171/0x340\n      worker_thread+0x277/0x3a0\n      kthread+0xf0/0x120\n      ret_from_fork+0x2d/0x50\n\nTo prevent this, flush the misc workqueue during device shutdown to\nensure that all pending work items are completed before the driver is\nunloaded.\n\nNote: This approach may slightly increase shutdown latency if the\nworkqueue contains jobs from other devices, but it ensures correctness\nand stability.",
  "id": "GHSA-c9qp-46j7-6qfj",
  "modified": "2026-10-15T03:34:56Z",
  "published": "2025-09-05T18:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39721"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
    },
    {
      "type": "WEB",
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3d4df408ba9bad2b205c7fb8afc1836a6a4ca88a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5858448a6c65d8ee3f8600570d3ce19febcb33be"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e59a52e429e13df3feb34f4853a8e36d121ed937"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fa4c14a82747886d333d8baef0d26da86ba1ccf7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fe546f5c50fc474daca6bee72caa7ab68a74c33d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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