{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "665338b2a7a0139337d1f85be65ed16e487f84c1"
            },
            {
              "fixed": "ec2501e361b08b50bcb1e7b3253fc861abbda28d"
            },
            {
              "fixed": "d02e2fbf60de46678e2ea698a6a904fd21e1cc31"
            },
            {
              "fixed": "48b26d48e76221dc90b02bf5428bab53643461ca"
            },
            {
              "fixed": "8f1ff8866cb9f655e5faea6994eb902960be8e04"
            },
            {
              "fixed": "3d07ca5c0fae311226f737963984bd94bb159a87"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.6.0"
            },
            {
              "fixed": "6.6.141"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.91"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.33"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45845.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: taprio: fix NULL pointer dereference in class dump\n\nWhen a TAPRIO child qdisc is deleted via RTM_DELQDISC, taprio_graft()\nis called with new == NULL and stores NULL into q-\u003eqdiscs[cl - 1].\nSubsequent RTM_GETTCLASS dump operations walk all classes via\ntaprio_walk() and call taprio_dump_class(), which calls taprio_leaf()\nreturning the NULL pointer, then dereferences it to read child-\u003ehandle,\ncausing a kernel NULL pointer dereference.\n\nThe bug is reachable with namespace-scoped CAP_NET_ADMIN on any kernel\nwith CONFIG_NET_SCH_TAPRIO enabled. On systems with unprivileged user\nnamespaces enabled, an unprivileged local user can trigger a kernel\npanic by creating a taprio qdisc inside a new network namespace,\ngrafting an explicit child qdisc, deleting it, and requesting a class\ndump. The RTM_GETTCLASS dump itself requires no capability.\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]\n RIP: 0010:taprio_dump_class (net/sched/sch_taprio.c:2478)\n Call Trace:\n  \u003cTASK\u003e\n  tc_fill_tclass (net/sched/sch_api.c:1966)\n  qdisc_class_dump (net/sched/sch_api.c:2326)\n  taprio_walk (net/sched/sch_taprio.c:2514)\n  tc_dump_tclass_qdisc (net/sched/sch_api.c:2352)\n  tc_dump_tclass_root (net/sched/sch_api.c:2370)\n  tc_dump_tclass (net/sched/sch_api.c:2431)\n  rtnl_dumpit (net/core/rtnetlink.c:6864)\n  netlink_dump (net/netlink/af_netlink.c:2325)\n  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)\n  netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n  \u003c/TASK\u003e\n\nFix this by substituting \u0026noop_qdisc when new is NULL in\ntaprio_graft(), a common pattern used by other qdiscs (e.g.,\nmultiq_graft()) to ensure the q-\u003eqdiscs[] slots are never NULL.\nThis makes control-plane dump paths safe without requiring individual\nNULL checks.\n\nSince the data-plane paths (taprio_enqueue and taprio_dequeue_from_txq)\npreviously had explicit NULL guards that would drop/skip the packet\ncleanly, update those checks to test for \u0026noop_qdisc instead. Without\nthis, packets would reach taprio_enqueue_one() which increments the root\nqdisc's qlen and backlog before calling the child's enqueue; noop_qdisc\ndrops the packet but those counters are never rolled back, permanently\ninflating the root qdisc's statistics.\n\nAfter this change *old can be a valid qdisc, NULL, or \u0026noop_qdisc.\nOnly call qdisc_put(*old) in the first case to avoid decreasing\nnoop_qdisc's refcount, which was never increased.",
  "id": "CVE-2026-45845",
  "modified": "2026-07-15T01:49:08.165060911Z",
  "published": "2026-05-27T09:24:48.438Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3d07ca5c0fae311226f737963984bd94bb159a87"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48b26d48e76221dc90b02bf5428bab53643461ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8f1ff8866cb9f655e5faea6994eb902960be8e04"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d02e2fbf60de46678e2ea698a6a904fd21e1cc31"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec2501e361b08b50bcb1e7b3253fc861abbda28d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45845.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45845"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "net/sched: taprio: fix NULL pointer dereference in class dump"
}