{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-37798", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.941Z", "datePublished": "2025-05-02T14:16:02.623Z", "dateUpdated": "2026-08-05T11:57:37.129Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:57:37.129Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncodel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()\n\nAfter making all ->qlen_notify() callbacks idempotent, now it is safe to\nremove the check of qlen!=0 from both fq_codel_dequeue() and\ncodel_qdisc_dequeue()." } ], "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 state is created and triggered through tc/rtnetlink qdisc configuration (RTM_NEWQDISC/RTM_NEWTCLASS/RTM_DELTCLASS) plus locally generated traffic over a loopback or veth device. There is no remote entry point into the qdisc class hierarchy setup.\nAC:L - The attacker controls every input: the qdisc hierarchy, CoDel's target/interval (unvalidated in codel_change()), the device MTU that defeats the backlog>mtu drop guard, the traffic that fills and empties the queue, and the moment the class is deleted. The inconsistent active-but-empty class state persists indefinitely, so no race window must be won.\nPR:L - Configuring qdiscs requires CAP_NET_ADMIN, but rtnetlink checks it via sk_ns_capable(sk, net->user_ns, CAP_NET_ADMIN), which any unprivileged local user obtains inside a `unshare -Urn` user+network namespace. Per kernel scoring guidance, tc/qdisc reachable through user namespaces is Low, not High.\nUI:N - The attacker performs every step — qdisc setup, traffic generation, and class deletion — within their own namespace. No victim action or interaction is needed.\nS:U - The corruption is confined to kernel heap objects and scheduler data structures managed by the same kernel security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed drr_class/qfq_class/hfsc_class remains linked in the parent's active list and rbtrees; after heap reclaim the attacker controls the object contents and the traversals read kernel pointers back out of it, yielding an arbitrary-read primitive and kernel address disclosure. Per guidance, use-after-free is High.\nI:H - Subsequent list_del/list_add and rb_erase operations write through pointers stored in the freed object, and drr_dequeue()/agg_dequeue() perform an indirect call via cl->qdisc->ops->peek() on reclaimed memory, giving a write primitive and control-flow hijack suitable for full privilege escalation.\nA:H - Even without successful exploitation, the dangling class in the active list/rbtree causes list and red-black-tree corruption and dereference of poisoned or freed pointers, producing a kernel oops or panic that can be triggered repeatedly by an unprivileged user." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_codel.c", "net/sched/sch_fq_codel.c" ], "versions": [ { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "7a742a9506849d1c1aa71e36c89855ceddc7d58e", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "cc71a757da78dd4aa1b4a9b19cb011833730ccf2", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "829c49b6b2ff45b043739168fd1245e4e1a91a30", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "2f9761a94bae33d26e6a81b31b36e7d776d93dc1", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "4d55144b12e742404bb3f8fee6038bafbf45619d", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "e73c838c80dccb9e4f19becc11d9f3cb4a27d483", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31", "status": "affected", "versionType": "git" }, { "version": "76e3cc126bb223013a6b9a0e2a51238d1ef2e409", "lessThan": "342debc12183b51773b3345ba267e9263bdfaaef", "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_codel.c", "net/sched/sch_fq_codel.c" ], "versions": [ { "version": "3.5", "status": "affected" }, { "version": "0", "lessThan": "3.5", "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": "6.1.135", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.88", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.24", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.12", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.3", "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": "3.5", "versionEndExcluding": "5.4.297" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.10.241" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.1.135" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.6.88" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.12.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.13.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.14.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7a742a9506849d1c1aa71e36c89855ceddc7d58e" }, { "url": "https://git.kernel.org/stable/c/cc71a757da78dd4aa1b4a9b19cb011833730ccf2" }, { "url": "https://git.kernel.org/stable/c/eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450" }, { "url": "https://git.kernel.org/stable/c/829c49b6b2ff45b043739168fd1245e4e1a91a30" }, { "url": "https://git.kernel.org/stable/c/2f9761a94bae33d26e6a81b31b36e7d776d93dc1" }, { "url": "https://git.kernel.org/stable/c/4d55144b12e742404bb3f8fee6038bafbf45619d" }, { "url": "https://git.kernel.org/stable/c/e73c838c80dccb9e4f19becc11d9f3cb4a27d483" }, { "url": "https://git.kernel.org/stable/c/a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31" }, { "url": "https://git.kernel.org/stable/c/342debc12183b51773b3345ba267e9263bdfaaef" } ], "title": "codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()", "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/2025/05/msg00045.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:55:29.865Z" } } ] } }