{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38083", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.981Z", "datePublished": "2025-06-20T11:21:51.554Z", "dateUpdated": "2026-08-05T11:59:21.321Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:59:21.321Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: prio: fix a race in prio_tune()\n\nGerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer\nfires at the wrong time.\n\nThe race is as follows:\n\nCPU 0 CPU 1\n[1]: lock root\n[2]: qdisc_tree_flush_backlog()\n[3]: unlock root\n |\n | [5]: lock root\n | [6]: rehash\n | [7]: qdisc_tree_reduce_backlog()\n |\n[4]: qdisc_put()\n\nThis can be abused to underflow a parent's qlen.\n\nCalling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()\nshould fix the race, because all packets will be purged from the qdisc\nbefore releasing the lock." } ], "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 code is reached only via `RTM_NEWQDISC` netlink messages (`tc qdisc change ... prio bands N`) combined with locally enqueued traffic; no data from a remote peer reaches `prio_tune()`.\nAC:L - The attacker controls both sides of the race — they set the SFQ child's `perturb` period and drop-forcing `flows`/`depth` parameters, choose when to issue the band-shrinking change, and can retry unboundedly until the timer lands in the unlocked window between `sch_tree_unlock()` and `qdisc_put()`.\nPR:L - The tc/qdisc netlink path is gated only by `netlink_net_capable(skb, CAP_NET_ADMIN)` against the netns' own user namespace, so an unprivileged user obtains it with `unshare -Urn` and can also autoload `sch_prio`/`sch_sfq` from that context.\nUI:N - The attacker performs every step themselves — building the prio/SFQ hierarchy, generating the traffic, and triggering the reconfiguration. No victim action is involved.\nS:U - The corrupted `qlen`/`backlog` accounting and any resulting memory corruption stay within the kernel's own security authority; this is standard local kernel privilege escalation with no VM, IOMMU, or sandbox boundary crossed.\nC:H - The double subtraction underflows the unsigned `q.qlen`, desynchronizing the qdisc tree so classes stay on parent active lists after their child qdiscs are freed, yielding a use-after-free on `struct Qdisc`/class objects that can be groomed into an arbitrary kernel-memory read.\nI:H - The same qlen-desync-to-UAF primitive gives control over reallocated heap objects and their function pointers and list heads, enabling arbitrary write and control-flow hijacking — the well-known net/sched local privilege escalation pattern.\nA:H - Even unweaponized, the underflowed `qlen` makes an empty qdisc appear to hold ~4 billion packets, causing dequeue-from-empty warnings, stalled transmit paths, and use-after-free oopses that panic the kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_prio.c" ], "versions": [ { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "53d11560e957d53ee87a0653d258038ce12361b7", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "4483d8b9127591c60c4eb789d6cab953bc4522a9", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "20f68e6a9e41693cb0e55e5b9ebbcb40983a4b8f", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "3aaa7c01cf19d9b9bb64b88b65c3a6fd05da2eb4", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "46c15c9d0f65c9ba857d63f53264f4b17e8a715f", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "e3f6745006dc9423d2b065b90f191cfa11b1b584", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "93f9eeb678d4c9c1abf720b3615fa8299a490845", "status": "affected", "versionType": "git" }, { "version": "7b8e0b6e659983154c8d7e756cdb833d89a3d4d7", "lessThan": "d35acc1be3480505b5931f17e4ea9b7617fea4d3", "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_prio.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.295", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.239", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.186", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.142", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.94", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.34", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.3", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "5.0", "versionEndExcluding": "5.4.295" }, { "vulnerable": true, "criteria": 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"versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/53d11560e957d53ee87a0653d258038ce12361b7" }, { "url": "https://git.kernel.org/stable/c/4483d8b9127591c60c4eb789d6cab953bc4522a9" }, { "url": "https://git.kernel.org/stable/c/20f68e6a9e41693cb0e55e5b9ebbcb40983a4b8f" }, { "url": "https://git.kernel.org/stable/c/3aaa7c01cf19d9b9bb64b88b65c3a6fd05da2eb4" }, { "url": "https://git.kernel.org/stable/c/46c15c9d0f65c9ba857d63f53264f4b17e8a715f" }, { "url": "https://git.kernel.org/stable/c/e3f6745006dc9423d2b065b90f191cfa11b1b584" }, { "url": "https://git.kernel.org/stable/c/93f9eeb678d4c9c1abf720b3615fa8299a490845" }, { "url": "https://git.kernel.org/stable/c/d35acc1be3480505b5931f17e4ea9b7617fea4d3" } ], "title": "net_sched: prio: fix a race in prio_tune()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:33:50.557Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:41:26.853Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" } ] } ] } }