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CVE-2026-64545

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net, bpf: check master for NULL in xdp_master_redirect() xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-27 21:17:07.130000
Last modified
2026-10-19 21:17:44.370000
View original CVE JSON 
{
  "id": "CVE-2026-64545",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-27T21:17:07.130",
  "lastModified": "2026-10-19T21:17:44.370",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet, bpf: check master for NULL in xdp_master_redirect()\n\nxdp_master_redirect() dereferences the result of\nnetdev_master_upper_dev_get_rcu() without a NULL check, but that helper\nreturns NULL when the receiving device has no upper-master adjacency.\n\nThe reach guard only checks netif_is_bond_slave(). On bond slave release\nbond_upper_dev_unlink() drops the upper-master adjacency before clearing\nIFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window\nstill passes netif_is_bond_slave() while master is already NULL, and\nfaults on master->flags at offset 0xb0:\n\n  BUG: kernel NULL pointer dereference, address: 00000000000000b0\n  RIP: 0010:xdp_master_redirect (net/core/filter.c:4432)\n  Call Trace:\n   xdp_master_redirect (net/core/filter.c:4432)\n   bpf_prog_run_generic_xdp (include/net/xdp.h:700)\n   do_xdp_generic (net/core/dev.c:5608)\n   __netif_receive_skb_one_core (net/core/dev.c:6204)\n   process_backlog (net/core/dev.c:6319)\n   __napi_poll (net/core/dev.c:7729)\n   net_rx_action (net/core/dev.c:7792)\n   handle_softirqs (kernel/softirq.c:622)\n   __dev_queue_xmit (include/linux/bottom_half.h:33)\n   packet_sendmsg (net/packet/af_packet.c:3082)\n   __sys_sendto (net/socket.c:2252)\n  Kernel panic - not syncing: Fatal exception in interrupt\n\nThe missing check dates back to the original code; commit 1921f91298d1\n(\"net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master\")\nlater added the master->flags read where the fault now lands but kept the\nunconditional deref. Check master for NULL before use; a NULL master is\ntreated the same as one that is not up."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/core/filter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "c99ca049e910d61ddbd28cc2c47242f2bfbb4970",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "e2a56441233131fe18a76001de347ecda217e40c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "3876318ea54e83eb70982b8280a3c5e4e32269bf",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "4edbcacca09f92b85d3951b6add11894b20a84bc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "03b743586a2469744e96e9c1015096d07240935d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "89c103d702b25ceb2d097faf854deb47b53b17ff",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "879af96ffd72706c6e3278ea6b45b0b0e37ec5d7",
              "lessThan": "e82d8cc4321c373dc46e741cd2dfdaa7921fddb7",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/core/filter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.212",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.178",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.145",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.97",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.40",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.5",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "affectedData": [
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
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              "lessThan": "*",
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              "status": "affected"
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        {
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          "defaultStatus": "unknown",
          "versions": [
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              "lessThan": "*",
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              "status": "affected"
            }
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        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.7",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
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              "version": "V3.1.7",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.7",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.6",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Siemens",
          "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "V3.1.7",
              "lessThan": "*",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:42:14.941919Z",
          "id": "CVE-2026-64545",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "references": [
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      "url": "https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d",
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}