FKIE_CVE-2026-74715

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-16 20:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix netns reference imbalance in conntrack kfuncs The opts argument of the BPF conntrack kfuncs can point to a shared map value. __bpf_nf_ct_lookup() and __bpf_nf_ct_alloc_entry() read opts->netns_id separately when acquiring and releasing the network namespace reference. The reference imbalance can occur as follows: CPU 0 CPU 1 read opts->netns_id (-1) skip get_net_ns_by_id() write opts->netns_id (id) read opts->netns_id (id) put_net(net) /* no matching get */ The reverse transition leaks the reference. Repeating the unmatched put can destroy a live namespace and crash later users. The kernel reported: Oops: general protection fault, probably for non-canonical address KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] RIP: 0010:bpf_prog_test_run_xdp+0x52c/0x1700 Call Trace: __sys_bpf+0x1662/0x50c0 __x64_sys_bpf+0x73/0xb0 do_syscall_64+0xf9/0x540 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: Fatal exception Snapshot every input field of opts with READ_ONCE() before validating or using it. The netns_id snapshot keeps the namespace get/put pair balanced, while the other snapshots keep the remaining options from changing partway through an invocation. The individual reads can still observe an inconsistent combination during a concurrent update, but each selected field value remains stable for that invocation.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4af94462c0ca2187a02a1a6641020ae888c74d5c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e5e060eb63d10b41ab60fd955649479d99b38210
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fdeba03fea78407a8c52faa99177c9f7f29f90eb
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nf_conntrack_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4af94462c0ca2187a02a1a6641020ae888c74d5c",
              "status": "affected",
              "version": "aed8ee7feb44b6537af1e0b4f03365d42928be38",
              "versionType": "git"
            },
            {
              "lessThan": "e5e060eb63d10b41ab60fd955649479d99b38210",
              "status": "affected",
              "version": "aed8ee7feb44b6537af1e0b4f03365d42928be38",
              "versionType": "git"
            },
            {
              "lessThan": "fdeba03fea78407a8c52faa99177c9f7f29f90eb",
              "status": "affected",
              "version": "aed8ee7feb44b6537af1e0b4f03365d42928be38",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nf_conntrack_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix netns reference imbalance in conntrack kfuncs\n\nThe opts argument of the BPF conntrack kfuncs can point to a shared\nmap value.  __bpf_nf_ct_lookup() and __bpf_nf_ct_alloc_entry() read\nopts-\u003enetns_id separately when acquiring and releasing the network\nnamespace reference.\n\nThe reference imbalance can occur as follows:\n\n  CPU 0                                  CPU 1\n  read opts-\u003enetns_id (-1)\n  skip get_net_ns_by_id()\n                                         write opts-\u003enetns_id (id)\n  read opts-\u003enetns_id (id)\n  put_net(net) /* no matching get */\n\nThe reverse transition leaks the reference.  Repeating the unmatched put\ncan destroy a live namespace and crash later users.\n\nThe kernel reported:\n\n  Oops: general protection fault, probably for non-canonical address\n  KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]\n  RIP: 0010:bpf_prog_test_run_xdp+0x52c/0x1700\n  Call Trace:\n   __sys_bpf+0x1662/0x50c0\n   __x64_sys_bpf+0x73/0xb0\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  Kernel panic - not syncing: Fatal exception\n\nSnapshot every input field of opts with READ_ONCE() before validating or\nusing it.  The netns_id snapshot keeps the namespace get/put pair\nbalanced, while the other snapshots keep the remaining options from\nchanging partway through an invocation.  The individual reads can still\nobserve an inconsistent combination during a concurrent update, but each\nselected field value remains stable for that invocation."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nbpf: Soluciona el desequilibrio de referencia de netns en las kfuncs de conntrack\n\nEl argumento opts de las kfuncs de conntrack de BPF puede apuntar a un valor de mapa compartido. __bpf_nf_ct_lookup() y __bpf_nf_ct_alloc_entry() leen opts -\u003e netns_id por separado al adquirir y liberar la referencia del espacio de nombres de red.\n\nEl desequilibrio de referencia puede ocurrir de la siguiente manera:\n\n  CPU 0                                  CPU 1\n  lee opts -\u003e netns_id (-1)\n  omite get_net_ns_by_id()\n                                         escribe opts -\u003e netns_id (id)\n  lee opts -\u003e netns_id (id)\n  put_net(net) /* no hay \u0027get\u0027 coincidente */\n\nLa transici\u00f3n inversa filtra la referencia. Repetir el \u0027put\u0027 sin coincidencia puede destruir un espacio de nombres activo y provocar un fallo en usuarios posteriores.\n\nEl kernel inform\u00f3:\n\n  Oops: fallo de protecci\u00f3n general, probablemente por direcci\u00f3n no can\u00f3nica\n  KASAN: null-ptr-deref en el rango [0x00000000000000e8-0x00000000000000ef]\n  RIP: 0010:bpf_prog_test_run_xdp+0x52c/0x1700\n  Call Trace:\n   __sys_bpf+0x1662/0x50c0\n   __x64_sys_bpf+0x73/0xb0\n   do_syscall_64+0xf9/0x540\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n  P\u00e1nico del kernel - no sincronizando: Excepci\u00f3n fatal\n\nRealice una instant\u00e1nea de cada campo de entrada de opts con READ_ONCE() antes de validarlo o usarlo. La instant\u00e1nea de netns_id mantiene equilibrado el par \u0027get/put\u0027 del espacio de nombres, mientras que las otras instant\u00e1neas evitan que las opciones restantes cambien a mitad de una invocaci\u00f3n. Las lecturas individuales a\u00fan pueden observar una combinaci\u00f3n inconsistente durante una actualizaci\u00f3n concurrente, pero cada valor de campo seleccionado permanece estable para esa invocaci\u00f3n."
    }
  ],
  "id": "CVE-2026-74715",
  "lastModified": "2026-10-16T20:17:54.220",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74715",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T19:15:29.946901Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-22T16:16:46.313",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4af94462c0ca2187a02a1a6641020ae888c74d5c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e5e060eb63d10b41ab60fd955649479d99b38210"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fdeba03fea78407a8c52faa99177c9f7f29f90eb"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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