{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38107", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.985Z", "datePublished": "2025-07-03T08:35:17.487Z", "dateUpdated": "2026-08-05T11:59:35.210Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:59:35.210Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: ets: fix a race in ets_qdisc_change()\n\nGerrard Tai reported a race condition in ETS, 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 through `RTM_NEWQDISC` netlink messages (`tc qdisc change ... ets bands N`) plus locally enqueued packets, requiring local system access. No remote peer input reaches `ets_qdisc_change()`.\nAC:L - The attacker controls both sides of the race — they configure the SFQ child's `perturb` period, choose when to issue the band-shrinking `tc` change, and can retry the sequence 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 via `unshare -Urn` and can also autoload `sch_ets`/`sch_sfq` from that context.\nUI:N - The attacker performs every step — creating the qdisc hierarchy, generating traffic, and triggering the change — entirely on their own. No victim action is involved.\nS:U - The corrupted `qlen`/`backlog` accounting and any resulting memory corruption are confined to 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 an unsigned `q.qlen`, desynchronizing the qdisc tree so classes remain on 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/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, stuck 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_ets.c" ], "versions": [ { "version": "699d82e9a6db29d509a71f1f2f4316231e6232e6", "lessThan": "eb7b74e9754e1ba2088f914ad1f57a778b11894b", "status": "affected", "versionType": "git" }, { "version": "ce881ddbdc028fb1988b66e40e45ca0529c23b46", "lessThan": "0b479d0aa488cb478eb2e1d8868be946ac8afb4f", "status": "affected", "versionType": "git" }, { "version": "b05972f01e7d30419987a1f221b5593668fd6448", "lessThan": "347867cb424edae5fec1622712c8dd0a2c42918f", "status": "affected", "versionType": "git" }, { "version": "b05972f01e7d30419987a1f221b5593668fd6448", "lessThan": "0383b25488a545be168744336847549d4a2d3d6c", "status": "affected", "versionType": "git" }, { "version": "b05972f01e7d30419987a1f221b5593668fd6448", "lessThan": "073f64c03516bcfaf790f8edc772e0cfb8a84ec3", "status": "affected", "versionType": "git" }, { "version": "b05972f01e7d30419987a1f221b5593668fd6448", "lessThan": "fed94bd51d62d2e0e006aa61480e94e5cd0582b0", "status": "affected", "versionType": "git" }, { "version": "b05972f01e7d30419987a1f221b5593668fd6448", "lessThan": "d92adacdd8c2960be856e0b82acc5b7c5395fddb", "status": "affected", "versionType": "git" }, { "version": "fffa19b5e58c34004a0d6f642d9c24b11d213994", "status": "affected", "versionType": "git" }, { "version": "fb155f6597cd7bc3aeed668c3bb15fc3b7cb257d", "status": "affected", "versionType": "git" }, { "version": "5.10.142", "lessThan": "5.10.239", "status": "affected", "versionType": "semver" }, { "version": "5.15.66", "lessThan": "5.15.186", "status": "affected", "versionType": "semver" }, { "version": "5.4.213", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.19.8", "lessThan": "5.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_ets.c" ], "versions": [ { "version": "6.0", "status": "affected" }, { "version": "0", "lessThan": "6.0", "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": "5.10.142", "versionEndExcluding": "5.10.239" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.66", "versionEndExcluding": "5.15.186" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.1.142" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.6.94" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.12.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.15.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndExcluding": "6.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.213" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/eb7b74e9754e1ba2088f914ad1f57a778b11894b" }, { "url": "https://git.kernel.org/stable/c/0b479d0aa488cb478eb2e1d8868be946ac8afb4f" }, { "url": "https://git.kernel.org/stable/c/347867cb424edae5fec1622712c8dd0a2c42918f" }, { "url": "https://git.kernel.org/stable/c/0383b25488a545be168744336847549d4a2d3d6c" }, { "url": "https://git.kernel.org/stable/c/073f64c03516bcfaf790f8edc772e0cfb8a84ec3" }, { "url": "https://git.kernel.org/stable/c/fed94bd51d62d2e0e006aa61480e94e5cd0582b0" }, { "url": "https://git.kernel.org/stable/c/d92adacdd8c2960be856e0b82acc5b7c5395fddb" } ], "title": "net_sched: ets: fix a race in ets_qdisc_change()", "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": "2025-11-03T17:34:09.673Z" } } ] } }