{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-37953", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.973Z", "datePublished": "2025-05-20T16:01:47.818Z", "dateUpdated": "2025-06-04T12:57:35.407Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-06-04T12:57:35.407Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: make htb_deactivate() idempotent\n\nAlan reported a NULL pointer dereference in htb_next_rb_node()\nafter we made htb_qlen_notify() idempotent.\n\nIt turns out in the following case it introduced some regression:\n\nhtb_dequeue_tree():\n |-> fq_codel_dequeue()\n |-> qdisc_tree_reduce_backlog()\n |-> htb_qlen_notify()\n |-> htb_deactivate()\n |-> htb_next_rb_node()\n |-> htb_deactivate()\n\nFor htb_next_rb_node(), after calling the 1st htb_deactivate(), the\nclprio[prio]->ptr could be already set to NULL, which means\nhtb_next_rb_node() is vulnerable here.\n\nFor htb_deactivate(), although we checked qlen before calling it, in\ncase of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again\nwhich triggers the warning inside.\n\nTo fix the issues here, we need to:\n\n1) Make htb_deactivate() idempotent, that is, simply return if we\n already call it before.\n2) Make htb_next_rb_node() safe against ptr==NULL.\n\nMany thanks to Alan for testing and for the reproducer."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_htb.c"], "versions": [{"version": "e6b45f4de763b00dc1c55e685e2dd1aaf525d3c1", "lessThan": "99ff8a20fd61315bf9ae627440a5ff07d22ee153", "status": "affected", "versionType": "git"}, {"version": "73cf6af13153d62f9b76eff422eea79dbc70f15e", "lessThan": "c928dd4f6bf0c25c72b11824a1e9ac9bd37296a0", "status": "affected", "versionType": "git"}, {"version": "bbbf5e0f87078b715e7a665d662a2c0e77f044ae", "lessThan": "31ff70ad39485698cf779f2078132d80b57f6c07", "status": "affected", "versionType": "git"}, {"version": "0a188c0e197383683fd093ab1ea6ce9a5869a6ea", "lessThan": "98cd7ed92753090a714f0802d4434314526fe61d", "status": "affected", "versionType": "git"}, {"version": "a61f1b5921761fbaf166231418bc1db301e5bf59", "lessThan": "c4792b9e38d2f61b07eac72f10909fa76130314b", "status": "affected", "versionType": "git"}, {"version": "5ba8b837b522d7051ef81bacf3d95383ff8edce5", "lessThan": "3769478610135e82b262640252d90f6efb05be71", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_htb.c"], "versions": [{"version": "6.1.138", "lessThan": "6.1.139", "status": "affected", "versionType": "semver"}, {"version": "6.6.90", "lessThan": "6.6.91", "status": "affected", "versionType": "semver"}, {"version": "6.12.28", "lessThan": "6.12.29", "status": "affected", "versionType": "semver"}, {"version": "6.14.6", "lessThan": "6.14.7", "status": "affected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.138", "versionEndExcluding": "6.1.139"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.90", "versionEndExcluding": "6.6.91"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.28", "versionEndExcluding": "6.12.29"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14.6", "versionEndExcluding": "6.14.7"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/99ff8a20fd61315bf9ae627440a5ff07d22ee153"}, {"url": "https://git.kernel.org/stable/c/c928dd4f6bf0c25c72b11824a1e9ac9bd37296a0"}, {"url": "https://git.kernel.org/stable/c/31ff70ad39485698cf779f2078132d80b57f6c07"}, {"url": "https://git.kernel.org/stable/c/98cd7ed92753090a714f0802d4434314526fe61d"}, {"url": "https://git.kernel.org/stable/c/c4792b9e38d2f61b07eac72f10909fa76130314b"}, {"url": "https://git.kernel.org/stable/c/3769478610135e82b262640252d90f6efb05be71"}], "title": "sch_htb: make htb_deactivate() idempotent", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: make htb_deactivate() idempotent\n\nAlan reported a NULL pointer dereference in htb_next_rb_node()\nafter we made htb_qlen_notify() idempotent.\n\nIt turns out in the following case it introduced some regression:\n\nhtb_dequeue_tree():\n |-> fq_codel_dequeue()\n |-> qdisc_tree_reduce_backlog()\n |-> htb_qlen_notify()\n |-> htb_deactivate()\n |-> htb_next_rb_node()\n |-> htb_deactivate()\n\nFor htb_next_rb_node(), after calling the 1st htb_deactivate(), the\nclprio[prio]->ptr could be already set to NULL, which means\nhtb_next_rb_node() is vulnerable here.\n\nFor htb_deactivate(), although we checked qlen before calling it, in\ncase of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again\nwhich triggers the warning inside.\n\nTo fix the issues here, we need to:\n\n1) Make htb_deactivate() idempotent, that is, simply return if we\n already call it before.\n2) Make htb_next_rb_node() safe against ptr==NULL.\n\nMany thanks to Alan for testing and for the reproducer."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sch_htb: hacer que htb_deactivate() sea idempotente. Alan inform\u00f3 una desreferencia de puntero NULL en htb_next_rb_node() despu\u00e9s de que htb_qlen_notify() fuera idempotente. Resulta que en el siguiente caso introdujo alguna regresi\u00f3n: htb_dequeue_tree(): |-> fq_codel_dequeue() |-> qdisc_tree_reduce_backlog() |-> htb_qlen_notify() |-> htb_deactivate() |-> htb_next_rb_node() |-> htb_deactivate() Para htb_next_rb_node(), despu\u00e9s de llamar al primer htb_deactivate(), el clprio[prio]->ptr podr\u00eda estar ya establecido en NULL, lo que significa que htb_next_rb_node() es vulnerable aqu\u00ed. Para htb_deactivate(), aunque verificamos qlen antes de llamarlo, en caso de qlen==0 despu\u00e9s de qdisc_tree_reduce_backlog(), podemos llamarlo nuevamente, lo que activa la advertencia interna. Para solucionar estos problemas, necesitamos: 1) Hacer que htb_deactivate() sea idempotente, es decir, que simplemente regrese si ya lo llamamos. 2) Hacer que htb_next_rb_node() sea seguro contra ptr==NULL. Muchas gracias a Alan por las pruebas y por el reproductor."}], "id": "CVE-2025-37953", "lastModified": "2025-06-04T13:15:27.437", "metrics": {}, "published": "2025-05-20T16:15:33.483", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/31ff70ad39485698cf779f2078132d80b57f6c07"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3769478610135e82b262640252d90f6efb05be71"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/98cd7ed92753090a714f0802d4434314526fe61d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/99ff8a20fd61315bf9ae627440a5ff07d22ee153"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c4792b9e38d2f61b07eac72f10909fa76130314b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c928dd4f6bf0c25c72b11824a1e9ac9bd37296a0"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: sch_htb: make htb_deactivate() idempotent", "id": "2367580", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2367580"}, "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": ["In the Linux kernel, the following vulnerability has been resolved:\nsch_htb: make htb_deactivate() idempotent\nAlan reported a NULL pointer dereference in htb_next_rb_node()\nafter we made htb_qlen_notify() idempotent.\nIt turns out in the following case it introduced some regression:\nhtb_dequeue_tree():\n|-> fq_codel_dequeue()\n|-> qdisc_tree_reduce_backlog()\n|-> htb_qlen_notify()\n|-> htb_deactivate()\n|-> htb_next_rb_node()\n|-> htb_deactivate()\nFor htb_next_rb_node(), after calling the 1st htb_deactivate(), the\nclprio[prio]->ptr could be already set to NULL, which means\nhtb_next_rb_node() is vulnerable here.\nFor htb_deactivate(), although we checked qlen before calling it, in\ncase of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again\nwhich triggers the warning inside.\nTo fix the issues here, we need to:\n1) Make htb_deactivate() idempotent, that is, simply return if we\nalready call it before.\n2) Make htb_next_rb_node() safe against ptr==NULL.\nMany thanks to Alan for testing and for the reproducer."], "name": "CVE-2025-37953", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-05-20T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-37953\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37953\nhttps://lore.kernel.org/linux-cve-announce/2025052001-CVE-2025-37953-d825@gregkh/T"], "threat_severity": "Moderate"}