{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-38553", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.025Z", "datePublished": "2025-08-19T06:06:53.204Z", "dateUpdated": "2025-08-19T06:06:53.204Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-08-19T06:06:53.204Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Restrict conditions for adding duplicating netems to qdisc tree\n\nnetem_enqueue's duplication prevention logic breaks when a netem\nresides in a qdisc tree with other netems - this can lead to a\nsoft lockup and OOM loop in netem_dequeue, as seen in [1].\nEnsure that a duplicating netem cannot exist in a tree with other\nnetems.\n\nPrevious approaches suggested in discussions in chronological order:\n\n1) Track duplication status or ttl in the sk_buff struct. Considered\ntoo specific a use case to extend such a struct, though this would\nbe a resilient fix and address other previous and potential future\nDOS bugs like the one described in loopy fun [2].\n\n2) Restrict netem_enqueue recursion depth like in act_mirred with a\nper cpu variable. However, netem_dequeue can call enqueue on its\nchild, and the depth restriction could be bypassed if the child is a\nnetem.\n\n3) Use the same approach as in 2, but add metadata in netem_skb_cb\nto handle the netem_dequeue case and track a packet's involvement\nin duplication. This is an overly complex approach, and Jamal\nnotes that the skb cb can be overwritten to circumvent this\nsafeguard.\n\n4) Prevent the addition of a netem to a qdisc tree if its ancestral\npath contains a netem. However, filters and actions can cause a\npacket to change paths when re-enqueued to the root from netem\nduplication, leading us to the current solution: prevent a\nduplicating netem from inhabiting the same tree as other netems.\n\n[1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/\n[2] https://lwn.net/Articles/719297/"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_netem.c"], "versions": [{"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "325f5ec67cc0a77f2d0d453445b9857f1cd06c76", "status": "affected", "versionType": "git"}, {"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "103c4e27ec9f5fe53022e46e976abf52c7221baf", "status": "affected", "versionType": "git"}, {"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "795cb393e38977aa991e70a9363da0ee734b2114", "status": "affected", "versionType": "git"}, {"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "250f8796006c0f2bc638ce545f601d49ae8d528b", "status": "affected", "versionType": "git"}, {"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "09317dfb681ac5a96fc69bea0c54441cf91b8270", "status": "affected", "versionType": "git"}, {"version": "0afb51e72855971dba83b3c6b70c547c2d1161fd", "lessThan": "ec8e0e3d7adef940cdf9475e2352c0680189d14e", "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_netem.c"], "versions": [{"version": "2.6.12", "status": "affected"}, {"version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.148", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.102", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.42", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.15.10", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.1", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17-rc1", "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": "2.6.12", "versionEndExcluding": "6.1.148"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.6.102"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.12.42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.15.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.16.1"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "6.17-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/325f5ec67cc0a77f2d0d453445b9857f1cd06c76"}, {"url": "https://git.kernel.org/stable/c/103c4e27ec9f5fe53022e46e976abf52c7221baf"}, {"url": "https://git.kernel.org/stable/c/795cb393e38977aa991e70a9363da0ee734b2114"}, {"url": "https://git.kernel.org/stable/c/250f8796006c0f2bc638ce545f601d49ae8d528b"}, {"url": "https://git.kernel.org/stable/c/09317dfb681ac5a96fc69bea0c54441cf91b8270"}, {"url": "https://git.kernel.org/stable/c/ec8e0e3d7adef940cdf9475e2352c0680189d14e"}], "title": "net/sched: Restrict conditions for adding duplicating netems to qdisc tree", "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: Restrict conditions for adding duplicating netems to qdisc tree\n\nnetem_enqueue's duplication prevention logic breaks when a netem\nresides in a qdisc tree with other netems - this can lead to a\nsoft lockup and OOM loop in netem_dequeue, as seen in [1].\nEnsure that a duplicating netem cannot exist in a tree with other\nnetems.\n\nPrevious approaches suggested in discussions in chronological order:\n\n1) Track duplication status or ttl in the sk_buff struct. Considered\ntoo specific a use case to extend such a struct, though this would\nbe a resilient fix and address other previous and potential future\nDOS bugs like the one described in loopy fun [2].\n\n2) Restrict netem_enqueue recursion depth like in act_mirred with a\nper cpu variable. However, netem_dequeue can call enqueue on its\nchild, and the depth restriction could be bypassed if the child is a\nnetem.\n\n3) Use the same approach as in 2, but add metadata in netem_skb_cb\nto handle the netem_dequeue case and track a packet's involvement\nin duplication. This is an overly complex approach, and Jamal\nnotes that the skb cb can be overwritten to circumvent this\nsafeguard.\n\n4) Prevent the addition of a netem to a qdisc tree if its ancestral\npath contains a netem. However, filters and actions can cause a\npacket to change paths when re-enqueued to the root from netem\nduplication, leading us to the current solution: prevent a\nduplicating netem from inhabiting the same tree as other netems.\n\n[1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/\n[2] https://lwn.net/Articles/719297/"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/sched: Restringir las condiciones para agregar netems duplicados al \u00e1rbol qdisc La l\u00f3gica de prevenci\u00f3n de duplicaci\u00f3n de netem_enqueue se rompe cuando un netem reside en un \u00e1rbol qdisc con otros netems: esto puede provocar un bloqueo suave y un bucle OOM en netem_dequeue, como se ve en [1]. Aseg\u00farese de que un netem duplicado no pueda existir en un \u00e1rbol con otros netems. Enfoques previos sugeridos en discusiones en orden cronol\u00f3gico: 1) Rastrear el estado de duplicaci\u00f3n o ttl en la estructura sk_buff. Se considera un caso de uso demasiado espec\u00edfico para extender dicha estructura, aunque esta ser\u00eda una soluci\u00f3n resiliente y abordar\u00eda otros errores de DOS anteriores y futuros potenciales como el descrito en loopy fun [2]. 2) Restringir la profundidad de recursi\u00f3n de netem_enqueue como en act_mirred con una variable por CPU. Sin embargo, netem_dequeue puede ejecutar la funci\u00f3n en cola en su elemento secundario, y la restricci\u00f3n de profundidad podr\u00eda omitirse si el elemento secundario es un netem. 3) Use el mismo enfoque que en el punto 2, pero agregue metadatos en netem_skb_cb para gestionar el caso de netem_dequeue y rastrear la participaci\u00f3n de un paquete en la duplicaci\u00f3n. Este es un enfoque excesivamente complejo, y Jamal se\u00f1ala que el skb_cb puede sobrescribirse para eludir esta protecci\u00f3n. 4) Evite la adici\u00f3n de un netem a un \u00e1rbol qdisc si su ruta ancestral contiene un netem. Sin embargo, los filtros y las acciones pueden provocar que un paquete cambie de ruta al volver a encolarse a la ra\u00edz desde la duplicaci\u00f3n de netem, lo que nos lleva a la soluci\u00f3n actual: evitar que un netem duplicado ocupe el mismo \u00e1rbol que otros netems. [1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/ [2] https://lwn.net/Articles/719297/"}], "id": "CVE-2025-38553", "lastModified": "2025-08-19T13:42:47.510", "metrics": {}, "published": "2025-08-19T06:15:33.407", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/09317dfb681ac5a96fc69bea0c54441cf91b8270"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/103c4e27ec9f5fe53022e46e976abf52c7221baf"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/250f8796006c0f2bc638ce545f601d49ae8d528b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/325f5ec67cc0a77f2d0d453445b9857f1cd06c76"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/795cb393e38977aa991e70a9363da0ee734b2114"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ec8e0e3d7adef940cdf9475e2352c0680189d14e"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: net/sched: Restrict conditions for adding duplicating netems to qdisc tree", "id": "2389333", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2389333"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2025-38553", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-08-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-38553\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-38553\nhttps://lore.kernel.org/linux-cve-announce/2025081956-CVE-2025-38553-4ecb@gregkh/T"], "threat_severity": "Important"}