net, bpf: check master for NULL in xdp_master_redirect()

{
  "id": "c78f413994356d8502291a7f8ab262f39ad69bde6b11bea598805347b4cff145",
  "url": "https://osv.dev/vulnerability/CVE-2026-64545",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net, bpf: check master for NULL in xdp_master_redirect()",
    "summary": "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",
    "evidence": "osv:CVE-2026-64545",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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            "value": "5.15.212",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.178",
            "evidence": "/affected/1/ranges"
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            "value": "6.6.145",
            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-64545",
      "aliases": [
        "CVE-2026-64545"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
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              "type": "GIT",
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            "ecosystem": "Linux"
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      ],
      "modified": "2026-10-28T02:30:39.082545889Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
        "https://git.kernel.org/stable/c/03b743586a2469744e96e9c1015096d07240935d",
        "https://git.kernel.org/stable/c/3876318ea54e83eb70982b8280a3c5e4e32269bf",
        "https://git.kernel.org/stable/c/4edbcacca09f92b85d3951b6add11894b20a84bc",
        "https://git.kernel.org/stable/c/89c103d702b25ceb2d097faf854deb47b53b17ff",
        "https://git.kernel.org/stable/c/c99ca049e910d61ddbd28cc2c47242f2bfbb4970",
        "https://git.kernel.org/stable/c/e2a56441233131fe18a76001de347ecda217e40c",
        "https://git.kernel.org/stable/c/e82d8cc4321c373dc46e741cd2dfdaa7921fddb7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64545.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64545",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64545.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64545",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 506767,
  "published_at": "2026-07-27T20:10:36.659+00:00"
}