{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1e052be69d045c8d0f82ff1116fd3e5a79661745"
            },
            {
              "fixed": "2e2f130951d34871b0643bf700164d97cff4b427"
            },
            {
              "fixed": "f8495d67434e1cb7e511297687ca55fdb28e4c20"
            },
            {
              "fixed": "81dd117c04422c6d0c7974aba9fa6a0ba370959b"
            },
            {
              "fixed": "1853f30cf5c84971f99788a76207c6f745380896"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.1.0"
            },
            {
              "fixed": "6.12.111"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97959.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_route: free emptied bucket on filter move\n\nroute4_change can move an existing filter to a different top-level\nbucket: route4_set_parms recomputes the handle from TCA_ROUTE4_TO/\nFROM/IIF, and the handle-mismatch check is gated on the 'new' flag, so\nfor an existing filter the new handle may differ from the old one and\nland in a different bucket. When this happens, the filter is unlinked\nfrom the old bucket, but the bucket itself is never freed once it goes\nempty. The stale empty bucket remains in head-\u003etable[], causing\nroute4_delete to report *last=false even after the last live filter is\ngone. That pins the empty tcf_proto and causes a leak.\n\nFix this by refcounting the filters linked to a bucket and freeing the\nbucket when the count drops to zero. The existing scan in route4_delete\ngoes away with it.\n\nThe count is updated at all sites that link or unlink a filter during add,\nchange and delete, and the bucket is dropped from head-\u003etable[] as soon as\nit reaches zero.\n\nConditions to recreate the bug:\n  CONFIG_NET_CLS_ROUTE4=y, CONFIG_NET_SCH_INGRESS=y, CONFIG_NET_CLS_ACT=y.\n\n  tc qdisc replace dev lo clsact\n  tc filter add dev lo ingress protocol ip pref 100 route from 1 to 1\n  tc filter change dev lo ingress protocol ip pref 100 handle 0x10001 \\\n    route from 1 to 2\n  tc filter del dev lo ingress protocol ip pref 100 handle 0x10002 \\\n    route from 1 to 2\n  tc filter show dev lo ingress | grep -c 'pref 100 route chain 0 '",
  "id": "CVE-2026-97959",
  "modified": "2026-09-27T03:30:50.873860816Z",
  "published": "2026-09-25T10:23:04.348Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1853f30cf5c84971f99788a76207c6f745380896"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2e2f130951d34871b0643bf700164d97cff4b427"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81dd117c04422c6d0c7974aba9fa6a0ba370959b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f8495d67434e1cb7e511297687ca55fdb28e4c20"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97959.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97959"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "net/sched: cls_route: free emptied bucket on filter move"
}