{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45845", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.078Z", "datePublished": "2026-05-27T09:24:48.438Z", "dateUpdated": "2026-05-27T09:24:48.438Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-27T09:24:48.438Z"}, "descriptions": [{"lang": "en", "value": "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->qdiscs[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->handle,\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 <TASK>\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 </TASK>\n\nFix this by substituting &noop_qdisc when new is NULL in\ntaprio_graft(), a common pattern used by other qdiscs (e.g.,\nmultiq_graft()) to ensure the q->qdiscs[] 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 &noop_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 &noop_qdisc.\nOnly call qdisc_put(*old) in the first case to avoid decreasing\nnoop_qdisc's refcount, which was never increased."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_taprio.c"], "versions": [{"version": "665338b2a7a0139337d1f85be65ed16e487f84c1", "lessThan": "ec2501e361b08b50bcb1e7b3253fc861abbda28d", "status": "affected", "versionType": "git"}, {"version": "665338b2a7a0139337d1f85be65ed16e487f84c1", "lessThan": "d02e2fbf60de46678e2ea698a6a904fd21e1cc31", "status": "affected", "versionType": "git"}, {"version": "665338b2a7a0139337d1f85be65ed16e487f84c1", "lessThan": "48b26d48e76221dc90b02bf5428bab53643461ca", "status": "affected", "versionType": "git"}, {"version": "665338b2a7a0139337d1f85be65ed16e487f84c1", "lessThan": "8f1ff8866cb9f655e5faea6994eb902960be8e04", "status": "affected", "versionType": "git"}, {"version": "665338b2a7a0139337d1f85be65ed16e487f84c1", "lessThan": "3d07ca5c0fae311226f737963984bd94bb159a87", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_taprio.c"], "versions": [{"version": "6.6", "status": "affected"}, {"version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.141", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.91", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.33", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.10", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1-rc2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.6.141"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.12.91"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.18.33"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.0.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.1-rc2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/ec2501e361b08b50bcb1e7b3253fc861abbda28d"}, {"url": "https://git.kernel.org/stable/c/d02e2fbf60de46678e2ea698a6a904fd21e1cc31"}, {"url": "https://git.kernel.org/stable/c/48b26d48e76221dc90b02bf5428bab53643461ca"}, {"url": "https://git.kernel.org/stable/c/8f1ff8866cb9f655e5faea6994eb902960be8e04"}, {"url": "https://git.kernel.org/stable/c/3d07ca5c0fae311226f737963984bd94bb159a87"}], "title": "net/sched: taprio: fix NULL pointer dereference in class dump", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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->qdiscs[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->handle,\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 <TASK>\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 </TASK>\n\nFix this by substituting &noop_qdisc when new is NULL in\ntaprio_graft(), a common pattern used by other qdiscs (e.g.,\nmultiq_graft()) to ensure the q->qdiscs[] 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 &noop_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 &noop_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", "lastModified": "2026-05-27T14:48:31.480", "metrics": {}, "published": "2026-05-27T11:16:23.960", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3d07ca5c0fae311226f737963984bd94bb159a87"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/48b26d48e76221dc90b02bf5428bab53643461ca"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8f1ff8866cb9f655e5faea6994eb902960be8e04"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d02e2fbf60de46678e2ea698a6a904fd21e1cc31"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ec2501e361b08b50bcb1e7b3253fc861abbda28d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{}