{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68815", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T10:30:51.047Z", "datePublished": "2026-01-13T15:29:19.789Z", "dateUpdated": "2026-08-05T12:11:43.729Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:11:43.729Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: ets: Remove drr class from the active list if it changes to strict\n\nWhenever a user issues an ets qdisc change command, transforming a\ndrr class into a strict one, the ets code isn't checking whether that\nclass was in the active list and removing it. This means that, if a\nuser changes a strict class (which was in the active list) back to a drr\none, that class will be added twice to the active list [1].\n\nDoing so with the following commands:\n\ntc qdisc add dev lo root handle 1: ets bands 2 strict 1\ntc qdisc add dev lo parent 1:2 handle 20: \\\n tbf rate 8bit burst 100b latency 1s\ntc filter add dev lo parent 1: basic classid 1:2\nping -c1 -W0.01 -s 56 127.0.0.1\ntc qdisc change dev lo root handle 1: ets bands 2 strict 2\ntc qdisc change dev lo root handle 1: ets bands 2 strict 1\nping -c1 -W0.01 -s 56 127.0.0.1\n\nWill trigger the following splat with list debug turned on:\n\n[ 59.279014][ T365] ------------[ cut here ]------------\n[ 59.279452][ T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.\n[ 59.280153][ T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220\n[ 59.280860][ T365] Modules linked in:\n[ 59.281165][ T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)\n[ 59.281977][ T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011\n[ 59.282391][ T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220\n[ 59.282842][ T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44\n...\n[ 59.288812][ T365] Call Trace:\n[ 59.289056][ T365] \n[ 59.289224][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.289546][ T365] ets_qdisc_change+0xd2b/0x1e80\n[ 59.289891][ T365] ? __lock_acquire+0x7e7/0x1be0\n[ 59.290223][ T365] ? __pfx_ets_qdisc_change+0x10/0x10\n[ 59.290546][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.290898][ T365] ? __mutex_trylock_common+0xda/0x240\n[ 59.291228][ T365] ? __pfx___mutex_trylock_common+0x10/0x10\n[ 59.291655][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.291993][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.292313][ T365] ? trace_contention_end+0xc8/0x110\n[ 59.292656][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.293022][ T365] ? srso_alias_return_thunk+0x5/0xfbef5\n[ 59.293351][ T365] tc_modify_qdisc+0x63a/0x1cf0\n\nFix this by always checking and removing an ets class from the active list\nwhen changing it to strict.\n\n[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663" } ], "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 - Triggering requires locally issued RTM_NEWQDISC traffic-control netlink operations; network traffic only establishes the required queued-class state.\nAC:L - The double insertion is deterministic, and the attacker controls the queued traffic, class transitions, band removal, and repeated dequeue pressure needed to expose the stale Qdisc.\nPR:L - rtnetlink requires CAP_NET_ADMIN in the socket's network namespace, which an unprivileged user can obtain by creating user and network namespaces where permitted.\nUI:N - No victim action is required after the attacker configures the ETS qdisc and generates traffic.\nS:U - Exploitation affects the host kernel but represents ordinary local kernel privilege escalation rather than crossing a separate virtualization or hardware security boundary.\nC:H - The corrupted active list can leave a class reachable while its child Qdisc is RCU-freed, producing a reclaimable use-after-free capable of exposing arbitrary kernel memory.\nI:H - The stale Qdisc is dereferenced through its ops->peek function pointer, allowing heap reclamation to support arbitrary writes or kernel control-flow hijacking.\nA:H - List hardening detects the double-add with a warning that may panic, while unhardened execution can cause stale-pointer or NULL dereferences, use-after-free, and kernel crashes." } ] } ], "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": "f517335a61ff8037b18ba1b0a002c1f82926a934", "lessThan": "58fdce6bc005e964f1dbc3ca716f5fe0f68839a2", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "8067db5c95aab9461d23117679338cd8869831fa", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "2f125ebe47d6369e562f3cbd9b6227cff51eaf34", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "cca2ed931b734fe48139bc6f020e47367346630f", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "43d9a530c8c094d137159784e7c951c65f11ec6c", "status": "affected", "versionType": "git" }, { "version": "cd9b50adc6bb9ad3f7d244590a389522215865c4", "lessThan": "b1e125ae425aba9b45252e933ca8df52a843ec70", "status": "affected", "versionType": "git" }, { "version": "d05330672afe2e142ba97e63bd7c1faef76781bb", "status": "affected", "versionType": "git" }, { "version": "5.10.62", "lessThan": "5.10.248", "status": "affected", "versionType": "semver" }, { "version": "5.13.14", "lessThan": "5.14", "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": "5.14", "status": "affected" }, { "version": "0", "lessThan": "5.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.248", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.198", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.160", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.120", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.64", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.3", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "5.10.62", "versionEndExcluding": "5.10.248" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "5.15.198" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.1.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.6.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.12.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.18.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.14", "versionEndExcluding": "6.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/58fdce6bc005e964f1dbc3ca716f5fe0f68839a2" }, { "url": "https://git.kernel.org/stable/c/02783a37cb1c0a2bd9fcba4ff1b81e6e209c7d87" }, { "url": "https://git.kernel.org/stable/c/8067db5c95aab9461d23117679338cd8869831fa" }, { "url": "https://git.kernel.org/stable/c/2f125ebe47d6369e562f3cbd9b6227cff51eaf34" }, { "url": "https://git.kernel.org/stable/c/cca2ed931b734fe48139bc6f020e47367346630f" }, { "url": "https://git.kernel.org/stable/c/43d9a530c8c094d137159784e7c951c65f11ec6c" }, { "url": "https://git.kernel.org/stable/c/b1e125ae425aba9b45252e933ca8df52a843ec70" } ], "title": "net/sched: ets: Remove drr class from the active list if it changes to strict", "x_generator": { "engine": "bippy-1.2.0" } } } }