{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38177", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.992Z", "datePublished": "2025-07-04T12:47:09.127Z", "dateUpdated": "2026-08-05T12:00:08.513Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:08.513Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_hfsc: make hfsc_qlen_notify() idempotent\n\nhfsc_qlen_notify() is not idempotent either and not friendly\nto its callers, like fq_codel_dequeue(). Let's make it idempotent\nto ease qdisc_tree_reduce_backlog() callers' life:\n\n1. update_vf() decreases cl->cl_nactive, so we can check whether it is\nnon-zero before calling it.\n\n2. eltree_remove() always removes RB node cl->el_node, but we can use\n RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached by configuring HFSC classes and child qdiscs via rtnetlink (`tc`) and driving local packet flow through them, which requires local system access. Remote packets alone cannot establish the required qdisc hierarchy.\nAC:L - The attacker fully controls every precondition — the qdisc/class topology, the child qdisc that re-enters `qdisc_tree_reduce_backlog()`, the packet, and the class deletion — and the sibling commit ships a deterministic shell reproducer. This is a reentrancy/accounting bug, not a race the attacker must win.\nPR:L - `tc` qdisc/class operations are gated by `netlink_net_capable(skb, CAP_NET_ADMIN)`, which resolves to `netlink_ns_capable(skb, sock_net(sk)->user_ns, ...)` — namespace-relative, so an unprivileged user obtains it with `unshare -Urn` and can build the full hierarchy on `lo` inside that netns.\nUI:N - The attacker performs the qdisc setup, packet transmission, and class deletion entirely on their own; no victim action or cooperation is needed.\nS:U - The corruption is confined to kernel memory within the same security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - Dangling `hfsc_class` rb_nodes left in `q->eligible`/`vt_tree` are dereferenced by `eltree_get_mindl()`/`vttree_get_minvt()` after `kfree()`, giving a use-after-free read over reclaimed heap contents the attacker can spray, enabling arbitrary kernel memory disclosure.\nI:H - Double `rb_erase()` on a stale node writes through an attacker-influenceable parent pointer, and subsequent `eltree_update()`/`rb_insert` operate on freed memory — yielding a write primitive; the same HFSC rbtree-corruption primitive has a public working local privilege escalation (CVE-2025-38001, \"rbtree family drama\").\nA:H - Red-black tree corruption and use-after-free on freed `hfsc_class` objects reliably produce oopses, KASAN splats, and kernel panics, taking the system down." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_hfsc.c" ], "versions": [ { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "9a5fd5c2f4d4afdd5e405083ee53e0789ce76956", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "a5efc95a33bd4fcb879250852828cc58c7862970", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "9030a91235ae4845ec71902c3e0cecfc9ed1f2df", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "d06476714d2819b550e0cc39222347e2c8941c9d", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "c1175c4ad01dbc9c979d099861fa90a754f72059", "status": "affected", "versionType": "git" }, { "version": "959466588aa7f84ccf79ae36a1d89542eaf9aaec", "lessThan": "51eb3b65544c9efd6a1026889ee5fb5aa62da3bb", "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_hfsc.c" ], "versions": [ { "version": "4.14", "status": "affected" }, { "version": "0", "lessThan": "4.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.297", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.241", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.190", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.138", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.90", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.28", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.6", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "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": "4.14", "versionEndExcluding": "5.4.297" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "5.10.241" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.1.138" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.6.90" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.12.28" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.14.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9a5fd5c2f4d4afdd5e405083ee53e0789ce76956" }, { "url": "https://git.kernel.org/stable/c/72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7" }, { "url": "https://git.kernel.org/stable/c/a5efc95a33bd4fcb879250852828cc58c7862970" }, { "url": "https://git.kernel.org/stable/c/0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87" }, { "url": "https://git.kernel.org/stable/c/9030a91235ae4845ec71902c3e0cecfc9ed1f2df" }, { "url": "https://git.kernel.org/stable/c/d06476714d2819b550e0cc39222347e2c8941c9d" }, { "url": "https://git.kernel.org/stable/c/c1175c4ad01dbc9c979d099861fa90a754f72059" }, { "url": "https://git.kernel.org/stable/c/51eb3b65544c9efd6a1026889ee5fb5aa62da3bb" } ], "title": "sch_hfsc: make hfsc_qlen_notify() idempotent", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/08/msg00010.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:58:30.487Z" } }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2025-38177", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2026-06-10T20:40:35.261574Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": 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