{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98017", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:19:56.069Z", "datePublished": "2026-09-25T10:23:39.107Z", "dateUpdated": "2026-09-25T14:41:50.690Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-25T14:41:50.690Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: defer qdisc freeing after failed creation\n\nAn RTM_NEWQDISC request can make clsact bind a populated shared ingress\nblock during ->init(), publishing an embedded mini_Qdisc to lockless\nreaders. If the same request has an invalid TCA_RATE, estimator setup\nfails after ->init(); the unwind removes the pointer but synchronously\nfrees its containing qdisc while tc_run() may still hold it.\n\nRetire failed qdiscs through the same RCU helper as normal destruction.\nInline the synchronous free into the callback now that no direct callers\nremain."}], "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 trigger is a local rtnetlink RTM_NEWQDISC message (tc_modify_qdisc -> qdisc_create) with a clsact kind, a shared TCA_INGRESS_BLOCK and an invalid TCA_RATE. Packets only drive the reader side (tc_run), and no remote peer supplies the input that causes the bug.\nAC:L - The attacker controls both sides of the race: they repeat the failing clsact create, which runs qdisc_free() with no grace period, while pushing traffic through their own veth/dummy device so that tc_run() dereferences the published miniq. No outside condition is needed.\nPR:L - tc_modify_qdisc only needs CAP_NET_ADMIN in the netns that owns the device, which an unprivileged user gets through unshare -Urn plus a self-created veth/dummy interface. That makes it reachable as PR:L rather than requiring init-namespace root.\nUI:N - The attacker performs every step themselves: creating the shared block and filter, sending the failing RTM_NEWQDISC, and generating traffic. No victim action is needed.\nS:U - The use-after-free and any resulting privilege escalation stay inside the same kernel security authority. No hypervisor or IOMMU boundary is crossed.\nC:H - The mini_Qdisc embedded in the freed qdisc (a kmalloc'd object, so its slot can be reclaimed) is read by tc_run: miniq->block and miniq->filter_list are passed to tcf_classify. With a sprayed replacement object, the attacker controls these pointers, which can be used to leak kernel memory.\nI:H - tc_run calls mini_qdisc_bstats_cpu_update(), which writes through the cpu_bstats pointer taken from the freed object, and tcf_classify follows a filter_list the attacker can control. After reclaim, this gives a controlled write and a path to hijacking control flow.\nA:H - Freeing the qdisc while RCU readers in tc_run still hold its embedded miniq leads to KASAN splats and oopses when the packet path touches the freed or reallocated memory. The result is a kernel crash."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/sch_generic.h", "net/sched/sch_api.c", "net/sched/sch_generic.c"], "versions": [{"version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "lessThan": "20bf6fa34b345333971bd4464a322cce87b83f4e", "status": "affected", "versionType": "git"}, {"version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "lessThan": "156a3bab69744e9225bb9eff8c5cc53da18d5a2e", "status": "affected", "versionType": "git"}, {"version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "lessThan": "5bfe927c5b4b290fad529186218c728589b4b101", "status": "affected", "versionType": "git"}, {"version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "lessThan": "e6662f2100f8d33b0f4d0047c219efd6bba186ea", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/sch_generic.h", "net/sched/sch_api.c", "net/sched/sch_generic.c"], "versions": [{"version": "4.16", "status": "affected"}, {"version": "0", "lessThan": "4.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc3", "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": "4.16", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.2.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.16", "versionEndExcluding": "7.3-rc3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/20bf6fa34b345333971bd4464a322cce87b83f4e"}, {"url": "https://git.kernel.org/stable/c/156a3bab69744e9225bb9eff8c5cc53da18d5a2e"}, {"url": "https://git.kernel.org/stable/c/5bfe927c5b4b290fad529186218c728589b4b101"}, {"url": "https://git.kernel.org/stable/c/e6662f2100f8d33b0f4d0047c219efd6bba186ea"}], "title": "net/sched: defer qdisc freeing after failed creation", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/sch_generic.h", "net/sched/sch_api.c", "net/sched/sch_generic.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "20bf6fa34b345333971bd4464a322cce87b83f4e", "status": "affected", "version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "versionType": "git"}, {"lessThan": "156a3bab69744e9225bb9eff8c5cc53da18d5a2e", "status": "affected", "version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "versionType": "git"}, {"lessThan": "5bfe927c5b4b290fad529186218c728589b4b101", "status": "affected", "version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "versionType": "git"}, {"lessThan": "e6662f2100f8d33b0f4d0047c219efd6bba186ea", "status": "affected", "version": "51ab2994c387c80b45caf8b8067b3f3b97771d25", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/sch_generic.h", "net/sched/sch_api.c", "net/sched/sch_generic.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.16"}, {"lessThan": "4.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.7", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: defer qdisc freeing after failed creation\n\nAn RTM_NEWQDISC request can make clsact bind a populated shared ingress\nblock during ->init(), publishing an embedded mini_Qdisc to lockless\nreaders. If the same request has an invalid TCA_RATE, estimator setup\nfails after ->init(); the unwind removes the pointer but synchronously\nfrees its containing qdisc while tc_run() may still hold it.\n\nRetire failed qdiscs through the same RCU helper as normal destruction.\nInline the synchronous free into the callback now that no direct callers\nremain."}], "id": "CVE-2026-98017", "lastModified": "2026-09-25T15:18:03.697", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-25T11:17:30.147", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/156a3bab69744e9225bb9eff8c5cc53da18d5a2e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/20bf6fa34b345333971bd4464a322cce87b83f4e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5bfe927c5b4b290fad529186218c728589b4b101"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e6662f2100f8d33b0f4d0047c219efd6bba186ea"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"created": "2026-09-25T19:30:20.142178+00:00", "updated": "2026-09-25T19:30:20.142183+00:00", "vendors": [], "weaknesses": ["CWE-416"]}