{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-39988",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2025-39988"
  ],
  "published": "2025-10-15T07:57:23Z",
  "summary": "can: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow\n\nSending an PF_PACKET allows to bypass the CAN framework logic and to\ndirectly reach the xmit() function of a CAN driver. The only check\nwhich is performed by the PF_PACKET framework is to make sure that\nskb->len fits the interface's MTU.\n\nUnfortunately, because the etas_es58x driver does not populate its\nnet_device_ops->ndo_change_mtu(), it is possible for an attacker to\nconfigure an invalid MTU by doing, for example:\n\n  $ ip link set can0 mtu 9999\n\nAfter doing so, the attacker could open a PF_PACKET socket using the\nETH_P_CANXL protocol:\n\n\tsocket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL));\n\nto inject a malicious CAN XL frames. For example:\n\n\tstruct canxl_frame frame = {\n\t\t.flags = 0xff,\n\t\t.len = 2048,\n\t};\n\nThe CAN drivers' xmit() function are calling can_dev_dropped_skb() to\ncheck that the skb is valid, unfortunately under above conditions, the\nmalicious packet is able to go through can_dev_dropped_skb() checks:\n\n  1. the skb->protocol is set to ETH_P_CANXL which is valid (the\n     function does not check the actual device capabilities).\n\n  2. the length is a valid CAN XL length.\n\nAnd so, es58x_start_xmit() receives a CAN XL frame which it is not\nable to correctly handle and will thus misinterpret it as a CAN(FD)\nframe.\n\nThis can result in a buffer overflow. For example, using the es581.4\nvariant, the frame will be dispatched to es581_4_tx_can_msg(), go\nthrough the last check at the beginning of this function:\n\n\tif (can_is_canfd_skb(skb))\n\t\treturn -EMSGSIZE;\n\nand reach this line:\n\n\tmemcpy(tx_can_msg->data, cf->data, cf->len);\n\nHere, cf->len corresponds to the flags field of the CAN XL frame. In\nour previous example, we set canxl_frame->flags to 0xff. Because the\nmaximum expected length is 8, a buffer overflow of 247 bytes occurs!\n\nPopulate net_device_ops->ndo_change_mtu() to ensure that the\ninterface's MTU can not be set to anything bigger than CAN_MTU or\nCANFD_MTU (depending on the device capabilities). By fixing the root\ncause, this prevents the buffer overflow.",
  "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": "6.1.155",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-39988"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/72de0facc50afdb101fb7197d880407f1abfc77f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c4e582e686c4d683c87f2b4a316385b3d81d370f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/cbc1de71766f326a44bb798aeae4a7ef4a081cc9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b26cccd87dcddc47b450a40f3b1ac3fe346efcff"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e587af2c89ecc6382c518febea52fa9ba81e47c0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/38c0abad45b190a30d8284a37264d2127a6ec303"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z"
  }
}