net: xps: reject an out of range traffic class

{
  "id": "a4b48f235b1370b695e7d04b802f615041d23b37788d4c9985a5ed2513455924",
  "url": "https://osv.dev/vulnerability/CVE-2026-98567",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: xps: reject an out of range traffic class",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: xps: reject an out of range traffic class Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store ",
    "evidence": "osv:CVE-2026-98567",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.271",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.222",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.189",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.158",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.112",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.55",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98567",
      "aliases": [
        "CVE-2026-98567"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "184c449f91fef521042970cca46bd5cdfc0e3a37"
                },
                {
                  "fixed": "967e10f40a0c6732db299cbe001df0e859196055"
                },
                {
                  "fixed": "1cb8e40525a72c9f1e1cf94c68c172b3b9bbdc81"
                },
                {
                  "fixed": "6ea8f643053f33622f9116e4e1db58306ece45e3"
                },
                {
                  "fixed": "9e841723ba482d41ecbf90241c756a16cdfea949"
                },
                {
                  "fixed": "eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f"
                },
                {
                  "fixed": "2cc1c3977acbffc417fb5b57699d1df3dcffb5fd"
                },
                {
                  "fixed": "930318290d8509e864c015fe6c9239470b3c579c"
                },
                {
                  "fixed": "4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98567.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.10.0"
                },
                {
                  "fixed": "5.10.271"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.222"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.189"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.158"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.112"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.55"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98567.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.542838265Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1cb8e40525a72c9f1e1cf94c68c172b3b9bbdc81",
        "https://git.kernel.org/stable/c/2cc1c3977acbffc417fb5b57699d1df3dcffb5fd",
        "https://git.kernel.org/stable/c/4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910",
        "https://git.kernel.org/stable/c/6ea8f643053f33622f9116e4e1db58306ece45e3",
        "https://git.kernel.org/stable/c/930318290d8509e864c015fe6c9239470b3c579c",
        "https://git.kernel.org/stable/c/967e10f40a0c6732db299cbe001df0e859196055",
        "https://git.kernel.org/stable/c/9e841723ba482d41ecbf90241c756a16cdfea949",
        "https://git.kernel.org/stable/c/eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98567.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98567",
        "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/2026/98xxx/CVE-2026-98567.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98567",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 492183,
  "published_at": "2026-10-18T15:18:33.721+00:00"
}