GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-93182 (GCVE-0-2026-93182)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:12 – Updated: 2026-09-17 16:12
VLAI
Title
sched/fair: Fix overflow in update_tg_cfs_runnable()
Summary
In the Linux kernel, the following vulnerability has been resolved: sched/fair: Fix overflow in update_tg_cfs_runnable() A divide-by-zero crash is observed when running hackbench: [14697.488452] CPU: 112 UID: 0 PID: 124791 Comm: hackbench Not tainted 7.1.0-rc2+ [14697.492627] RIP: 0010:propagate_entity_load_avg+0x35f/0x3e0 [14697.506799] <TASK> [14697.507411] __dequeue_task+0x2b4/0xc70 [14697.508677] dequeue_task_fair+0x36/0x370 [14697.509047] dequeue_task+0x101/0x2f0 [14697.509426] __schedule+0x1b1/0x1a00 [14697.510868] anon_pipe_read+0x3da/0x450 [14697.511400] vfs_read+0x361/0x390 [14697.512053] __x64_sys_read+0x19/0x30 The divide-by-zero happens here: if (scale_load_down(gcfs_rq->load.weight)) { load_sum = div_u64(gcfs_rq->avg.load_sum, scale_load_down(gcfs_rq->load.weight)); } gcfs_rq->load.weight is an insane large value and is truncated to the lower 32 bits by div_u64, which happen to be 0. Using AI for investigation, the cause is a u32 overflow in update_tg_cfs_runnable(), and flat pickup became a victim when using tg_tasks(): u32 new_sum, divider; ... new_sum = se->avg.runnable_avg * divider; <-- boom The following sequence shows how this triggers the crash: propagate_entity_load_avg() update_tg_cfs_runnable() # u32 overflow corrupts runnable_sum __update_load_avg_cfs_rq() ___update_load_avg() # computes insane runnable_avg update_tg_load_avg() # propagates to tg->runnable_avg update_cfs_group() calc_concur_shares() tg_tasks() # long-to-int truncation, negative nr reweight_entity() # corrupted se->load.weight update_load_add() # corrupted cfs_rq->load.weight propagate_entity_load_avg() update_tg_cfs_load() div_u64() # divide-by-zero Fix by widening new_sum from u32 to u64 (no need to force tg_tasks() to return unsigned long after this fix)
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < 39d707097a0820c6e87eff4195f0940e8ff1147e (git)
Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < 69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75 (git)
Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < 7cc237e3bc1733928313d2462b413ae441b0eef3 (git)
Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < 18fdd0978ec3dda0ff6865cd273e47e022180710 (git)
Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < f94e62d21faad5e244d0874598a4d0ebbc0ea405 (git)
Affected: 95246d1ec80b8d19d882cd8eb7ad094e63b41bb8 , < 4f166adb5cb0525d9e32d45729fd8f28c80acbee (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.17
Unaffected: 0 , < 5.17 (semver)
Unaffected: 6.1.188 , ≤ 6.1.* (semver)
Unaffected: 6.6.157 , ≤ 6.6.* (semver)
Unaffected: 6.12.110 , ≤ 6.12.* (semver)
Unaffected: 6.18.52 , ≤ 6.18.* (semver)
Unaffected: 7.2.6 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/fair.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "39d707097a0820c6e87eff4195f0940e8ff1147e",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            },
            {
              "lessThan": "69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            },
            {
              "lessThan": "7cc237e3bc1733928313d2462b413ae441b0eef3",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            },
            {
              "lessThan": "18fdd0978ec3dda0ff6865cd273e47e022180710",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            },
            {
              "lessThan": "f94e62d21faad5e244d0874598a4d0ebbc0ea405",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            },
            {
              "lessThan": "4f166adb5cb0525d9e32d45729fd8f28c80acbee",
              "status": "affected",
              "version": "95246d1ec80b8d19d882cd8eb7ad094e63b41bb8",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/fair.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.188",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.110",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.52",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/fair: Fix overflow in update_tg_cfs_runnable()\n\nA divide-by-zero crash is observed when running hackbench:\n\n   [14697.488452] CPU: 112 UID: 0 PID: 124791 Comm: hackbench Not tainted 7.1.0-rc2+\n   [14697.492627] RIP: 0010:propagate_entity_load_avg+0x35f/0x3e0\n   [14697.506799]  \u003cTASK\u003e\n   [14697.507411]  __dequeue_task+0x2b4/0xc70\n   [14697.508677]  dequeue_task_fair+0x36/0x370\n   [14697.509047]  dequeue_task+0x101/0x2f0\n   [14697.509426]  __schedule+0x1b1/0x1a00\n   [14697.510868]  anon_pipe_read+0x3da/0x450\n   [14697.511400]  vfs_read+0x361/0x390\n   [14697.512053]  __x64_sys_read+0x19/0x30\n\nThe divide-by-zero happens here:\n\n  if (scale_load_down(gcfs_rq-\u003eload.weight)) {\n           load_sum = div_u64(gcfs_rq-\u003eavg.load_sum,\n                              scale_load_down(gcfs_rq-\u003eload.weight));\n  }\n\ngcfs_rq-\u003eload.weight is an insane large value and is truncated\nto the lower 32 bits by div_u64, which happen to be 0.\n\nUsing AI for investigation, the cause is a u32 overflow in\nupdate_tg_cfs_runnable(), and flat pickup became a victim when using\ntg_tasks():\n\n   u32 new_sum, divider;\n   ...\n   new_sum = se-\u003eavg.runnable_avg * divider; \u003c-- boom\n\nThe following sequence shows how this triggers the crash:\n\n   propagate_entity_load_avg()\n     update_tg_cfs_runnable()     # u32 overflow corrupts runnable_sum\n\n   __update_load_avg_cfs_rq()\n     ___update_load_avg()         # computes insane runnable_avg\n   update_tg_load_avg()           # propagates to tg-\u003erunnable_avg\n\n   update_cfs_group()\n     calc_concur_shares()\n       tg_tasks()                 # long-to-int truncation, negative nr\n     reweight_entity()            # corrupted se-\u003eload.weight\n       update_load_add()          # corrupted cfs_rq-\u003eload.weight\n\n   propagate_entity_load_avg()\n     update_tg_cfs_load()\n       div_u64()                  # divide-by-zero\n\nFix by widening new_sum from u32 to u64 (no need to force tg_tasks()\nto return unsigned long after this fix)"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-17T16:12:09.381Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/39d707097a0820c6e87eff4195f0940e8ff1147e"
        },
        {
          "url": "https://git.kernel.org/stable/c/69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75"
        },
        {
          "url": "https://git.kernel.org/stable/c/7cc237e3bc1733928313d2462b413ae441b0eef3"
        },
        {
          "url": "https://git.kernel.org/stable/c/18fdd0978ec3dda0ff6865cd273e47e022180710"
        },
        {
          "url": "https://git.kernel.org/stable/c/f94e62d21faad5e244d0874598a4d0ebbc0ea405"
        },
        {
          "url": "https://git.kernel.org/stable/c/4f166adb5cb0525d9e32d45729fd8f28c80acbee"
        }
      ],
      "title": "sched/fair: Fix overflow in update_tg_cfs_runnable()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-93182",
    "datePublished": "2026-09-17T16:12:09.381Z",
    "dateReserved": "2026-09-17T16:02:15.091Z",
    "dateUpdated": "2026-09-17T16:12:09.381Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-93182\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-17T17:18:14.153\",\"lastModified\":\"2026-09-17T17:18:14.153\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsched/fair: Fix overflow in update_tg_cfs_runnable()\\n\\nA divide-by-zero crash is observed when running hackbench:\\n\\n   [14697.488452] CPU: 112 UID: 0 PID: 124791 Comm: hackbench Not tainted 7.1.0-rc2+\\n   [14697.492627] RIP: 0010:propagate_entity_load_avg+0x35f/0x3e0\\n   [14697.506799]  \u003cTASK\u003e\\n   [14697.507411]  __dequeue_task+0x2b4/0xc70\\n   [14697.508677]  dequeue_task_fair+0x36/0x370\\n   [14697.509047]  dequeue_task+0x101/0x2f0\\n   [14697.509426]  __schedule+0x1b1/0x1a00\\n   [14697.510868]  anon_pipe_read+0x3da/0x450\\n   [14697.511400]  vfs_read+0x361/0x390\\n   [14697.512053]  __x64_sys_read+0x19/0x30\\n\\nThe divide-by-zero happens here:\\n\\n  if (scale_load_down(gcfs_rq-\u003eload.weight)) {\\n           load_sum = div_u64(gcfs_rq-\u003eavg.load_sum,\\n                              scale_load_down(gcfs_rq-\u003eload.weight));\\n  }\\n\\ngcfs_rq-\u003eload.weight is an insane large value and is truncated\\nto the lower 32 bits by div_u64, which happen to be 0.\\n\\nUsing AI for investigation, the cause is a u32 overflow in\\nupdate_tg_cfs_runnable(), and flat pickup became a victim when using\\ntg_tasks():\\n\\n   u32 new_sum, divider;\\n   ...\\n   new_sum = se-\u003eavg.runnable_avg * divider; \u003c-- boom\\n\\nThe following sequence shows how this triggers the crash:\\n\\n   propagate_entity_load_avg()\\n     update_tg_cfs_runnable()     # u32 overflow corrupts runnable_sum\\n\\n   __update_load_avg_cfs_rq()\\n     ___update_load_avg()         # computes insane runnable_avg\\n   update_tg_load_avg()           # propagates to tg-\u003erunnable_avg\\n\\n   update_cfs_group()\\n     calc_concur_shares()\\n       tg_tasks()                 # long-to-int truncation, negative nr\\n     reweight_entity()            # corrupted se-\u003eload.weight\\n       update_load_add()          # corrupted cfs_rq-\u003eload.weight\\n\\n   propagate_entity_load_avg()\\n     update_tg_cfs_load()\\n       div_u64()                  # divide-by-zero\\n\\nFix by widening new_sum from u32 to u64 (no need to force tg_tasks()\\nto return unsigned long after this fix)\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"kernel/sched/fair.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"39d707097a0820c6e87eff4195f0940e8ff1147e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"7cc237e3bc1733928313d2462b413ae441b0eef3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"18fdd0978ec3dda0ff6865cd273e47e022180710\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"f94e62d21faad5e244d0874598a4d0ebbc0ea405\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"95246d1ec80b8d19d882cd8eb7ad094e63b41bb8\",\"lessThan\":\"4f166adb5cb0525d9e32d45729fd8f28c80acbee\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"kernel/sched/fair.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.17\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.17\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.188\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.157\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.110\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.52\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.6\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/18fdd0978ec3dda0ff6865cd273e47e022180710\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/39d707097a0820c6e87eff4195f0940e8ff1147e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4f166adb5cb0525d9e32d45729fd8f28c80acbee\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7cc237e3bc1733928313d2462b413ae441b0eef3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f94e62d21faad5e244d0874598a4d0ebbc0ea405\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.