CVE-2025-68815 (GCVE-0-2025-68815)

Vulnerability from cvelistv5 – Published: 2026-01-13 15:29 – Updated: 2026-01-13 15:29
VLAI?
Title
net/sched: ets: Remove drr class from the active list if it changes to strict
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: ets: Remove drr class from the active list if it changes to strict Whenever a user issues an ets qdisc change command, transforming a drr class into a strict one, the ets code isn't checking whether that class was in the active list and removing it. This means that, if a user changes a strict class (which was in the active list) back to a drr one, that class will be added twice to the active list [1]. Doing so with the following commands: tc qdisc add dev lo root handle 1: ets bands 2 strict 1 tc qdisc add dev lo parent 1:2 handle 20: \ tbf rate 8bit burst 100b latency 1s tc filter add dev lo parent 1: basic classid 1:2 ping -c1 -W0.01 -s 56 127.0.0.1 tc qdisc change dev lo root handle 1: ets bands 2 strict 2 tc qdisc change dev lo root handle 1: ets bands 2 strict 1 ping -c1 -W0.01 -s 56 127.0.0.1 Will trigger the following splat with list debug turned on: [ 59.279014][ T365] ------------[ cut here ]------------ [ 59.279452][ T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0. [ 59.280153][ T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220 [ 59.280860][ T365] Modules linked in: [ 59.281165][ T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary) [ 59.281977][ T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 59.282391][ T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220 [ 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 ... [ 59.288812][ T365] Call Trace: [ 59.289056][ T365] <TASK> [ 59.289224][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.289546][ T365] ets_qdisc_change+0xd2b/0x1e80 [ 59.289891][ T365] ? __lock_acquire+0x7e7/0x1be0 [ 59.290223][ T365] ? __pfx_ets_qdisc_change+0x10/0x10 [ 59.290546][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.290898][ T365] ? __mutex_trylock_common+0xda/0x240 [ 59.291228][ T365] ? __pfx___mutex_trylock_common+0x10/0x10 [ 59.291655][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.291993][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.292313][ T365] ? trace_contention_end+0xc8/0x110 [ 59.292656][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.293022][ T365] ? srso_alias_return_thunk+0x5/0xfbef5 [ 59.293351][ T365] tc_modify_qdisc+0x63a/0x1cf0 Fix this by always checking and removing an ets class from the active list when changing it to strict. [1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: cd9b50adc6bb9ad3f7d244590a389522215865c4 , < 8067db5c95aab9461d23117679338cd8869831fa (git)
Affected: cd9b50adc6bb9ad3f7d244590a389522215865c4 , < 2f125ebe47d6369e562f3cbd9b6227cff51eaf34 (git)
Affected: cd9b50adc6bb9ad3f7d244590a389522215865c4 , < cca2ed931b734fe48139bc6f020e47367346630f (git)
Affected: cd9b50adc6bb9ad3f7d244590a389522215865c4 , < 43d9a530c8c094d137159784e7c951c65f11ec6c (git)
Affected: cd9b50adc6bb9ad3f7d244590a389522215865c4 , < b1e125ae425aba9b45252e933ca8df52a843ec70 (git)
Affected: f517335a61ff8037b18ba1b0a002c1f82926a934 (git)
Affected: d05330672afe2e142ba97e63bd7c1faef76781bb (git)
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    Linux Linux Affected: 5.14
Unaffected: 0 , < 5.14 (semver)
Unaffected: 6.1.160 , ≤ 6.1.* (semver)
Unaffected: 6.6.120 , ≤ 6.6.* (semver)
Unaffected: 6.12.64 , ≤ 6.12.* (semver)
Unaffected: 6.18.3 , ≤ 6.18.* (semver)
Unaffected: 6.19-rc2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_ets.c"
          ],
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              "versionType": "git"
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              "version": "d05330672afe2e142ba97e63bd7c1faef76781bb",
              "versionType": "git"
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          "product": "Linux",
          "programFiles": [
            "net/sched/sch_ets.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "5.14"
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              "version": "0",
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              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.120",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.64",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.160",
                  "versionStartIncluding": "5.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.120",
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                  "versionEndExcluding": "6.12.64",
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                  "versionEndExcluding": "6.19-rc2",
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              "negate": false,
              "operator": "OR"
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      "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\u0027t 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 \u003c0f\u003e 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]  \u003cTASK\u003e\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"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-13T15:29:19.789Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "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"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-68815",
    "datePublished": "2026-01-13T15:29:19.789Z",
    "dateReserved": "2025-12-24T10:30:51.047Z",
    "dateUpdated": "2026-01-13T15:29:19.789Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-68815\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-01-13T16:16:03.757\",\"lastModified\":\"2026-01-13T16:16:03.757\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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\u0027t 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 \u003c0f\u003e 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]  \u003cTASK\u003e\\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\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2f125ebe47d6369e562f3cbd9b6227cff51eaf34\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/43d9a530c8c094d137159784e7c951c65f11ec6c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8067db5c95aab9461d23117679338cd8869831fa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b1e125ae425aba9b45252e933ca8df52a843ec70\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cca2ed931b734fe48139bc6f020e47367346630f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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