{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-22004",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-22004"
  ],
  "published": "2025-04-03T07:18:16Z",
  "summary": "net: atm: fix use after free in lec_send()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: atm: fix use after free in lec_send()\n\nThe ->send() operation frees skb so save the length before calling\n->send() to avoid a use after free.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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": "6.1.132",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-22004"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/50e288097c2c6e5f374ae079394436fc29d1e88e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8cd90c7db08f32829bfa1b5b2b11fbc542afbab7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/82d9084a97892de1ee4881eb5c17911fcd9be6f6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/51e8be9578a2e74f9983d8fd8de8cafed191f30c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9566f6ee13b17a15d0a47667ad1b1893c539f730"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/326223182e4703cde99fdbd36d07d0b3de9980fb"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f3271f7548385e0096739965961c7cbf7e6b4762"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f3009d0d6ab78053117f8857b921a8237f4d17b3"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 8.6,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - The vulnerable code is the TX path of the `lec%d` netdevice, and an unauthenticated remote host reaches it with no local access \u2014 a packet sent to the LANE-attached host elicits a reply transmitted through `lec_start_xmit()` \u2192 `lec_send()`, and in the proxy/bridge mode LANE explicitly supports, a frame received on an Ethernet segment is forwarded straight out the ELAN into the same path. No adjacency is required since a LANE client is an ordinary routed IP host.\nAC:L - The read-after-free is unconditional on every successful send, with no race and no memory-layout precondition: `adummy_send()` and `atmtcp_v_send()` free the skb synchronously and return 0, after which `lec_send()` always dereferences `skb->len`. Even against hardware ATM drivers that free asynchronously via `vcc->pop()`, the attacker simply drives traffic to hit it repeatedly.\nPR:N - Triggering requires no credentials on the target \u2014 a remote peer merely causes a frame to be transmitted on the emulated LAN. The `capable(CAP_NET_ADMIN)` checks on `ATMLEC_CTRL`/`ATMLEC_DATA` gate only the administrative LANE setup, not the vulnerable transmit path, which is also open to any unprivileged local process via a plain `sendto()`.\nUI:N - No victim action is needed; the freed-object read happens automatically in the netdevice transmit path and in the `lec_arp_check_expire()` workqueue drain.\nS:U - The stale read and the corrupted statistics counter are entirely within the kernel's own security authority, with no crossing into a hypervisor, IOMMU, or sandbox boundary.\nC:L - The stale `skb->len` from the freed skbuff is accumulated into `dev->stats.tx_bytes`, which any user can read via `/sys/class/net/lec0/statistics/tx_bytes` or `/proc/net/dev`, yielding a repeatable kernel-heap disclosure \u2014 but it is strictly bounded to 4 bytes from one fixed offset of a `SLAB_NO_MERGE` cache, so it is a limited leak rather than an arbitrary read.\nI:L - Nothing is written into the freed object, so there is no memory corruption or write primitive; the only integrity effect is that attacker-influenced garbage is folded into the interface's `tx_bytes` counter, falsifying kernel-reported accounting data.\nA:H - This is a genuine use-after-free, and on KASAN- or KFENCE-instrumented kernels the access raises a slab-use-after-free report that panics the machine outright under `panic_on_warn`, which is common in production and CI fleets."
    }
  }
}