{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72036", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.901Z", "datePublished": "2026-08-15T05:51:57.012Z", "dateUpdated": "2026-10-16T15:53:17.333Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:39:39.361Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked\n\nmultiq_dequeue() takes a packet from a band's child with a direct\n->dequeue() call after multiq_peek() peeked it. When the child is\nnon-work-conserving the peek stashes the skb in the child's gso_skb, so\nthe direct dequeue returns a different skb and orphans the stash,\ndesyncing the child's qlen/backlog. With a qfq child reached through a\npeeking parent (e.g. tbf) this re-enters the child on an emptied list and\ndereferences NULL, panicking the kernel from softirq on ordinary egress.\n\nTake the packet through qdisc_dequeue_peeked(), as sch_prio already does\nand as sch_red and sch_sfb were just fixed to do. The helper is a no-op\nwhen the child has no stash, so a work-conserving child is unaffected." } ], "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 - Exploitation requires locally installing a tbf→multiq→qfq hierarchy on a multiqueue netdev via RTM_NEWQDISC/tc netlink before egress can hit multiq_dequeue(); per kernel CNA guidance, tc/qdisc configuration bugs are Local even though the panic fires from softirq during packet transmission.\nAC:L - Once the hierarchy exists, the peek/dequeue mismatch is a deterministic logic bug: tbf peek stashes the QFQ child's skb in gso_skb, then multiq_dequeue's direct child->dequeue() bypasses that stash and re-enters QFQ on an emptied list; ping reproducers for sch_red/sfb show no race or layout dependency.\nPR:L - RTM_NEWQDISC and qdisc grafting are gated by netlink_net_capable(skb, CAP_NET_ADMIN) in rtnetlink_rcv_msg, evaluated against net->user_ns; unprivileged users obtain CAP_NET_ADMIN via user/network namespaces (unshare -Urn) without init-namespace root.\nUI:N - No victim interaction is needed after qdisc setup; triggering the NULL dereference requires only attacker-generated egress traffic (e.g., ping) through the defective tbf→multiq→qfq dequeue path.\nS:U - The qlen/backlog desync, orphaned gso_skb stash, and resulting kernel panic occur entirely within the host kernel packet scheduler; no VM, IOMMU, or sandbox security boundary is crossed.\nC:H - Peek stashes the skb in the non-work-conserving child's gso_skb while direct dequeue returns a different packet, desyncing qlen/backlog—the same scheduler-accounting corruption primitive seen in prior net/sched CVEs and capable of exposing corrupted or freed kernel scheduler memory.\nI:H - Orphaning the gso_skb stash corrupts parent/child queue linkage and QFQ aggregate scheduling state; inconsistent qlen drives invalid list operations in qfq_dequeue, yielding attacker-influenced memory corruption beyond the demonstrated NULL dereference.\nA:H - The desync re-enters QFQ on an emptied aggregate list and dereferences NULL in qfq_dequeue from softirq during ordinary egress, panicking the kernel as documented in the fix commit and matching KASAN null-ptr-deref traces in the related sch_red/sch_sfb reports." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_multiq.c" ], "versions": [ { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "3e5fd9d14f2d228e7260251f2e4a1d41ba8f705a", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "eb1a9637f0bd84b5db8803af65dfb1f44785406f", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "7a5a1582710981ef6637de9f074a60a5b1d63222", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "86a61e46a1919e8abf4d227c204773dabb24068a", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "1b9cc255e8089606b92b2adf504e334573682821", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "5889064919a1e5c0a9469c54895000414fc46944", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "fffeb2ab5eeb823d4c2330571a098f63237c9049", "status": "affected", "versionType": "git" }, { "version": "77be155cba4e163e8bba9fd27222a8b6189ec4f7", "lessThan": "54f6b0c843e228d499eb4b6bbb89df68cad9ad5d", "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_multiq.c" ], "versions": [ { "version": "2.6.29", "status": "affected" }, { "version": "0", "lessThan": "2.6.29", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "2.6.29", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3e5fd9d14f2d228e7260251f2e4a1d41ba8f705a" }, { "url": "https://git.kernel.org/stable/c/eb1a9637f0bd84b5db8803af65dfb1f44785406f" }, { "url": "https://git.kernel.org/stable/c/7a5a1582710981ef6637de9f074a60a5b1d63222" }, { "url": "https://git.kernel.org/stable/c/86a61e46a1919e8abf4d227c204773dabb24068a" }, { "url": "https://git.kernel.org/stable/c/1b9cc255e8089606b92b2adf504e334573682821" }, { "url": "https://git.kernel.org/stable/c/5889064919a1e5c0a9469c54895000414fc46944" }, { "url": "https://git.kernel.org/stable/c/fffeb2ab5eeb823d4c2330571a098f63237c9049" }, { "url": "https://git.kernel.org/stable/c/54f6b0c843e228d499eb4b6bbb89df68cad9ad5d" } ], "title": "net/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-72036", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T15:50:31.248558Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:53:17.333Z" } } ] } }