CVE-2026-97996 (GCVE-0-2026-97996)

Vulnerability from cvelistv5 – Published: 2026-09-25 10:23 – Updated: 2026-09-25 10:23
VLAI
Title
virtio: fix use-after-free in unregister_virtio_device()
Summary
In the Linux kernel, the following vulnerability has been resolved: virtio: fix use-after-free in unregister_virtio_device() device_unregister() is device_del() plus put_device(). When the caller holds no extra reference, that drops the last one and runs the release callback, which for several transports frees the memory the embedded struct virtio_device sits in. unregister_virtio_device() then calls virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed object. Affected transports are the ones whose release callback frees and whose remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml, mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because virtio_pci_remove() brackets the call with get_device() and put_device(). Remove the debugfs entries before the device can go away. They are only accessed through the protected debugfs interface, so debugfs_remove_recursive() waits for in-progress file operations before returning. Tearing them down while the device is still alive is therefore safe. Reproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG by unbinding a virtio-uml device: BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d Read of size 8 at addr 00000000616e0b10 by task init/1 __asan_report_load8_noabort virtio_debug_device_exit+0x36/0x4d unregister_virtio_device+0x48/0x75 virtio_uml_remove platform_remove device_release_driver_internal unbind_store Freed by task 1: kfree virtio_uml_release_dev device_release kobject_put put_device device_unregister With this applied, the report is gone and unbind is clean.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 96a8326d69fffd7e8c2eb737dc060d8009a33b39 , < 951cad50cba89e736afdee4a730e0e52f9245c9b (git)
Affected: 96a8326d69fffd7e8c2eb737dc060d8009a33b39 , < 77dbd10a701a30fdfea5c3bb7a29163128f9a9c7 (git)
Affected: 96a8326d69fffd7e8c2eb737dc060d8009a33b39 , < caf042153016d651b55d0fb4a63cdf7d0d23dee2 (git)
Affected: 96a8326d69fffd7e8c2eb737dc060d8009a33b39 , < 3f9a0fceb730f5107d52421ead5568eae25a0049 (git)
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Linux Linux Affected: 6.10
Unaffected: 0 , < 6.10 (semver)
Unaffected: 6.12.111 , ≤ 6.12.* (semver)
Unaffected: 6.18.53 , ≤ 6.18.* (semver)
Unaffected: 7.2.7 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc3 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/virtio/virtio.c"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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          "vendor": "Linux",
          "versions": [
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              "version": "6.10"
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              "status": "unaffected",
              "version": "0",
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              "versionType": "semver"
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      "cpeApplicability": [
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio: fix use-after-free in unregister_virtio_device()\n\ndevice_unregister() is device_del() plus put_device(). When the caller\nholds no extra reference, that drops the last one and runs the release\ncallback, which for several transports frees the memory the embedded\nstruct virtio_device sits in. unregister_virtio_device() then calls\nvirtio_debug_device_exit(), which reads dev-\u003edebugfs_dir out of the freed\nobject.\n\nAffected transports are the ones whose release callback frees and whose\nremove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml,\nmlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because\nvirtio_pci_remove() brackets the call with get_device() and put_device().\n\nRemove the debugfs entries before the device can go away. They are only\naccessed through the protected debugfs interface, so\ndebugfs_remove_recursive() waits for in-progress file operations before\nreturning. Tearing them down while the device is still alive is therefore\nsafe.\n\nReproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG\nby unbinding a virtio-uml device:\n\n  BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d\n  Read of size 8 at addr 00000000616e0b10 by task init/1\n   __asan_report_load8_noabort\n   virtio_debug_device_exit+0x36/0x4d\n   unregister_virtio_device+0x48/0x75\n   virtio_uml_remove\n   platform_remove\n   device_release_driver_internal\n   unbind_store\n\n  Freed by task 1:\n   kfree\n   virtio_uml_release_dev\n   device_release\n   kobject_put\n   put_device\n   device_unregister\n\nWith this applied, the report is gone and unbind is clean."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-25T10:23:26.913Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/951cad50cba89e736afdee4a730e0e52f9245c9b"
        },
        {
          "url": "https://git.kernel.org/stable/c/77dbd10a701a30fdfea5c3bb7a29163128f9a9c7"
        },
        {
          "url": "https://git.kernel.org/stable/c/caf042153016d651b55d0fb4a63cdf7d0d23dee2"
        },
        {
          "url": "https://git.kernel.org/stable/c/3f9a0fceb730f5107d52421ead5568eae25a0049"
        }
      ],
      "title": "virtio: fix use-after-free in unregister_virtio_device()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97996",
    "datePublished": "2026-09-25T10:23:26.913Z",
    "dateReserved": "2026-09-25T10:18:58.209Z",
    "dateUpdated": "2026-09-25T10:23:26.913Z",
    "state": "PUBLISHED"
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      "date": "2026-09-27",
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      "percentile": "0.05386"
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                "programFiles": [
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                    "versionType": "semver"
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        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio: fix use-after-free in unregister_virtio_device()\n\ndevice_unregister() is device_del() plus put_device(). When the caller\nholds no extra reference, that drops the last one and runs the release\ncallback, which for several transports frees the memory the embedded\nstruct virtio_device sits in. unregister_virtio_device() then calls\nvirtio_debug_device_exit(), which reads dev-\u003edebugfs_dir out of the freed\nobject.\n\nAffected transports are the ones whose release callback frees and whose\nremove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml,\nmlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because\nvirtio_pci_remove() brackets the call with get_device() and put_device().\n\nRemove the debugfs entries before the device can go away. They are only\naccessed through the protected debugfs interface, so\ndebugfs_remove_recursive() waits for in-progress file operations before\nreturning. Tearing them down while the device is still alive is therefore\nsafe.\n\nReproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG\nby unbinding a virtio-uml device:\n\n  BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d\n  Read of size 8 at addr 00000000616e0b10 by task init/1\n   __asan_report_load8_noabort\n   virtio_debug_device_exit+0x36/0x4d\n   unregister_virtio_device+0x48/0x75\n   virtio_uml_remove\n   platform_remove\n   device_release_driver_internal\n   unbind_store\n\n  Freed by task 1:\n   kfree\n   virtio_uml_release_dev\n   device_release\n   kobject_put\n   put_device\n   device_unregister\n\nWith this applied, the report is gone and unbind is clean."
          }
        ],
        "id": "CVE-2026-97996",
        "lastModified": "2026-09-25T11:17:27.880",
        "metrics": {},
        "published": "2026-09-25T11:17:27.880",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          },
          {
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          },
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            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    }
  }
}



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