{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-52503",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2023-52503"
  ],
  "published": "2024-03-02T21:53:07Z",
  "summary": "tee: amdtee: fix use-after-free vulnerability in amdtee_close_session",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntee: amdtee: fix use-after-free vulnerability in amdtee_close_session\n\nThere is a potential race condition in amdtee_close_session that may\ncause use-after-free in amdtee_open_session. For instance, if a session\nhas refcount == 1, and one thread tries to free this session via:\n\n    kref_put(&sess->refcount, destroy_session);\n\nthe reference count will get decremented, and the next step would be to\ncall destroy_session(). However, if in another thread,\namdtee_open_session() is called before destroy_session() has completed\nexecution, alloc_session() may return 'sess' that will be freed up\nlater in destroy_session() leading to use-after-free in\namdtee_open_session.\n\nTo fix this issue, treat decrement of sess->refcount and removal of\n'sess' from session list in destroy_session() as a critical section, so\nthat it is executed atomically.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.59",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-52503"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/da7ce52a2f6c468946195b116615297d3d113a27"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1680c82929bc14d706065f123dab77f2f1293116"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/60c3e7a00db954947c265b55099c21b216f2a05c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1c95574350cd63bc3c5c2fa06658010768f2a0ce"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f4384b3e54ea813868bb81a861bf5b2406e15d8f"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:24:39Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerability is reached through TEE_IOC_OPEN_SESSION and TEE_IOC_CLOSE_SESSION ioctls on the amdtee client device (/dev/tee*), requiring local process access to the character device rather than network or adjacent packet delivery.\nAC:L - The attacker fully controls both sides of the race by sharing one tee_context fd across threads and concurrently issuing open_session and close_session for the same TA; per guidance, attacker-driven races are AC:L.\nPR:L - amdtee registers an unprivileged client tee device with no capability checks in tee_open or the ioctl path; access is only via device-node permissions, and normal TEE clients on AMD TEE deployments (e.g. Chromebooks) are unprivileged local users.\nUI:N - Exploitation requires only the attacker's own open/close session ioctls; no victim action such as mounting a filesystem or opening a malicious file is needed.\nS:U - The use-after-free is in the Linux kernel amdtee driver and impacts the host kernel's authority; this is standard local privilege escalation, not a VM/IOMMU/sandbox boundary crossing.\nC:H - Use-after-free of struct amdtee_session lets the attacker reclaim and control the freed object contents, enabling arbitrary kernel memory disclosure primitives.\nI:H - After the free, amdtee_open_session continues to write session_info and sess_mask under sess->lock on the dangling pointer, yielding a heap UAF write usable for control-flow hijacking or arbitrary kernel writes.\nA:H - Any use-after-free of a kernel session object can oops or panic the kernel when the dangling pointer is locked or dereferenced, so availability impact is High."
    }
  }
}