fkie_cve-2025-40223
Vulnerability from fkie_nvd
Published
2025-12-04 16:16
Modified
2025-12-04 17:15
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: most: usb: Fix use-after-free in hdm_disconnect hdm_disconnect() calls most_deregister_interface(), which eventually unregisters the MOST interface device with device_unregister(iface->dev). If that drops the last reference, the device core may call release_mdev() immediately while hdm_disconnect() is still executing. The old code also freed several mdev-owned allocations in hdm_disconnect() and then performed additional put_device() calls. Depending on refcount order, this could lead to use-after-free or double-free when release_mdev() ran (or when unregister paths also performed puts). Fix by moving the frees of mdev-owned allocations into release_mdev(), so they happen exactly once when the device is truly released, and by dropping the extra put_device() calls in hdm_disconnect() that are redundant after device_unregister() and most_deregister_interface(). This addresses the KASAN slab-use-after-free reported by syzbot in hdm_disconnect(). See report and stack traces in the bug link below.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/33daf469f5294b9d07c4fc98216cace9f4f34cc6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4b1270902609ef0d935ed2faa2ea6d122bd148f5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/578eb18cd111addec94c43f61cd4b4429e454809
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/72427dc6f87523995f4e6ae35a948bb2992cabce
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f93a84ffb884d761a9d4e869ba29c238711e81f1
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmost: usb: Fix use-after-free in hdm_disconnect\n\nhdm_disconnect() calls most_deregister_interface(), which eventually\nunregisters the MOST interface device with device_unregister(iface-\u003edev).\nIf that drops the last reference, the device core may call release_mdev()\nimmediately while hdm_disconnect() is still executing.\n\nThe old code also freed several mdev-owned allocations in\nhdm_disconnect() and then performed additional put_device() calls.\nDepending on refcount order, this could lead to use-after-free or\ndouble-free when release_mdev() ran (or when unregister paths also\nperformed puts).\n\nFix by moving the frees of mdev-owned allocations into release_mdev(),\nso they happen exactly once when the device is truly released, and by\ndropping the extra put_device() calls in hdm_disconnect() that are\nredundant after device_unregister() and most_deregister_interface().\n\nThis addresses the KASAN slab-use-after-free reported by syzbot in\nhdm_disconnect(). See report and stack traces in the bug link below."
    }
  ],
  "id": "CVE-2025-40223",
  "lastModified": "2025-12-04T17:15:08.283",
  "metrics": {},
  "published": "2025-12-04T16:16:14.767",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/33daf469f5294b9d07c4fc98216cace9f4f34cc6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4b1270902609ef0d935ed2faa2ea6d122bd148f5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/578eb18cd111addec94c43f61cd4b4429e454809"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/72427dc6f87523995f4e6ae35a948bb2992cabce"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f93a84ffb884d761a9d4e869ba29c238711e81f1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.