Vulnerability-Lookup

FKIE_CVE-2026-64374

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-10-19 21:17

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT RT migration is done aggressively. When a CPU schedules out a high priority RT task for a lower priority task, it will look to see if there's any RT tasks that are waiting to run on another CPU that is of higher priority than the task this CPU is about to run. If it finds one, it will pull that task over to the CPU and allow it to run there instead. Normally, this pulling is done by looking at the RT overloaded mask (rto) which contains all the CPUs in the scheduler domain with RT tasks that are waiting to run due to a higher priority RT task currently running on their CPU. The CPU that is about to schedule a lower priority task will grab the rq lock of the overloaded CPU and move the RT task from that CPU's runqueue to the local one and schedule the higher priority RT task. This caused issues when a lot of CPUs would schedule a lower priority task at the same time. They would all try to grab the same runqueue lock of the CPU with the overloaded RT tasks. Only the first CPU that got in will get that task. All the others would wait until they got the runqueue lock and see there's nothing to pull and do nothing. On systems with lots of CPUs, this caused a large latency (up to 500us) which is beyond what PREEMPT_RT is to allow. The solution to that was to create an RT_PUSH_IPI logic. When any CPU wanted to pull a task, instead of grabbing the runqueue lock of the overloaded CPU, it would start by sending an IPI to the overloaded CPU, and that IPI handler would have the CPU with the waiting RT task do a push instead. Then that handler would send an IPI to the next CPU with overloaded RT tasks, and so on. Note, after the first CPU starts this process, if another CPU wanted to do a pull, it would see that the process has already begun and would only increment a counter to have the IPIs continue again. The RT_PUSH_IPI solved the latency problem with PREEMPT_RT but could cause a new issue with non PREEMPT_RT. Namely, softirqs run in a threaded context on PREEMPT_RT but they can run in an interrupt context in non-RT. If an IPI lands on a CPU that has just woken up multiple RT tasks and the current CPU is running a non RT or a low priority RT task, instead of doing a push, it would simply do a schedule on that CPU. But if a softirq was also executing on this CPU, the schedule would need to wait until the softirq finished. Until then, the CPU would still be considered overloaded as there are RT tasks still waiting to run on it. A live lock occurred on a workload that was doing heavy networking traffic on a large machine where the softirqs would run 500us out of 750us. And it would also be waking up RT tasks, causing the RT pull logic to be constantly executed. When a softirq triggered on a CPU with RT tasks queued but not running yet, and the other CPUs would see this CPU as being overloaded, they would send an IPI over to it. The CPU would notice that the waiting RT tasks are of higher priority than the currently running task and simply schedule that CPU instead. But because the softirq was executing, before it could schedule, it would receive another IPI to do the same. The amount of IPIs would slow down the currently running softirq so much that before it could return back to task context, it would execute another softirq never allowing the CPU to schedule. This live locked that CPU. As RT_PUSH_IPI was created to help PREEMPT_RT, make it default off if PREEMPT_RT is not enabled.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/44aae426dbfd51286f7eb601cfa14bc32164812a	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4bd0da48fbc1dbef6774175129107fbbdd353e26	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/860aaff72c8446fed5e576249e19952883a18885	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/89237c8fc15d8016a194076e648ccb57d75e65ae	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a18f80bf5359238c4f067d691b96af00286fdd89	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b99f04ae3d200d2f8844aa29145bd18eccbeecde	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d8312a56d9a162e3ec76476aa487e7d20bc602e9	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dd29c017aed628076e915fe4cdfb5392fd4c5cab	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*

JSON

To clipboard

{
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT\n\nRT migration is done aggressively. When a CPU schedules out a high\npriority RT task for a lower priority task, it will look to see if there\u0027s\nany RT tasks that are waiting to run on another CPU that is of higher\npriority than the task this CPU is about to run. If it finds one, it will\npull that task over to the CPU and allow it to run there instead.\n\nNormally, this pulling is done by looking at the RT overloaded mask (rto)\nwhich contains all the CPUs in the scheduler domain with RT tasks that are\nwaiting to run due to a higher priority RT task currently running on their\nCPU. The CPU that is about to schedule a lower priority task will grab the\nrq lock of the overloaded CPU and move the RT task from that CPU\u0027s runqueue\nto the local one and schedule the higher priority RT task.\n\nThis caused issues when a lot of CPUs would schedule a lower priority task\nat the same time. They would all try to grab the same runqueue lock of\nthe CPU with the overloaded RT tasks. Only the first CPU that got in will\nget that task. All the others would wait until they got the runqueue lock\nand see there\u0027s nothing to pull and do nothing. On systems with lots of\nCPUs, this caused a large latency (up to 500us) which is beyond what\nPREEMPT_RT is to allow.\n\nThe solution to that was to create an RT_PUSH_IPI logic. When any CPU\nwanted to pull a task, instead of grabbing the runqueue lock of the\noverloaded CPU, it would start by sending an IPI to the overloaded CPU,\nand that IPI handler would have the CPU with the waiting RT task do a push\ninstead. Then that handler would send an IPI to the next CPU with\noverloaded RT tasks, and so on. Note, after the first CPU starts this\nprocess, if another CPU wanted to do a pull, it would see that the process\nhas already begun and would only increment a counter to have the IPIs\ncontinue again.\n\nThe RT_PUSH_IPI solved the latency problem with PREEMPT_RT but could cause\na new issue with non PREEMPT_RT. Namely, softirqs run in a threaded\ncontext on PREEMPT_RT but they can run in an interrupt context in non-RT.\n\nIf an IPI lands on a CPU that has just woken up multiple RT tasks and the\ncurrent CPU is running a non RT or a low priority RT task, instead of\ndoing a push, it would simply do a schedule on that CPU. But if a softirq\nwas also executing on this CPU, the schedule would need to wait until the\nsoftirq finished. Until then, the CPU would still be considered overloaded\nas there are RT tasks still waiting to run on it.\n\nA live lock occurred on a workload that was doing heavy networking traffic\non a large machine where the softirqs would run 500us out of 750us. And it\nwould also be waking up RT tasks, causing the RT pull logic to be\nconstantly executed.\n\nWhen a softirq triggered on a CPU with RT tasks queued but not running\nyet, and the other CPUs would see this CPU as being overloaded, they would\nsend an IPI over to it. The CPU would notice that the waiting RT tasks are\nof higher priority than the currently running task and simply schedule\nthat CPU instead. But because the softirq was executing, before it could\nschedule, it would receive another IPI to do the same. The amount of IPIs\nwould slow down the currently running softirq so much that before it could\nreturn back to task context, it would execute another softirq never\nallowing the CPU to schedule. This live locked that CPU.\n\nAs RT_PUSH_IPI was created to help PREEMPT_RT, make it default off if\nPREEMPT_RT is not enabled."
    }
  ],
  "id": "CVE-2026-64374",
  "lastModified": "2026-10-19T21:17:33.617",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
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        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
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        "ssvcData": {
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          "options": [
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              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T15:39:36.572926Z",
          "version": "2.0.3"
        }
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    ]
  },
  "published": "2026-07-25T10:17:20.433",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/44aae426dbfd51286f7eb601cfa14bc32164812a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
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      "description": [
        {
          "lang": "en",
          "value": "CWE-667"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    },
    {
      "description": [
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          "lang": "en",
          "value": "CWE-835"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}

CVE-2026-64374 (GCVE-0-2026-64374)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:50 – Updated: 2026-10-19 20:38

Title

sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT

Summary

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-16 15:39 UTC

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

8 references

URL	Tags
https://git.kernel.org/stable/c/b99f04ae3d200d2f8…
https://git.kernel.org/stable/c/d8312a56d9a162e3e…
https://git.kernel.org/stable/c/44aae426dbfd51286…
https://git.kernel.org/stable/c/860aaff72c8446fed…
https://git.kernel.org/stable/c/89237c8fc15d8016a…
https://git.kernel.org/stable/c/4bd0da48fbc1dbef6…
https://git.kernel.org/stable/c/a18f80bf5359238c4…
https://git.kernel.org/stable/c/dd29c017aed628076…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < b99f04ae3d200d2f8844aa29145bd18eccbeecde (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < d8312a56d9a162e3ec76476aa487e7d20bc602e9 (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < 44aae426dbfd51286f7eb601cfa14bc32164812a (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < 860aaff72c8446fed5e576249e19952883a18885 (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < 89237c8fc15d8016a194076e648ccb57d75e65ae (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < 4bd0da48fbc1dbef6774175129107fbbdd353e26 (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < a18f80bf5359238c4f067d691b96af00286fdd89 (git) Affected: b6366f048e0caff28af5335b7af2031266e1b06b , < dd29c017aed628076e915fe4cdfb5392fd4c5cab (git)
Linux	Linux	Affected: 4.1 Unaffected: 0 , < 4.1 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-64374",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T15:39:36.572926Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-835",
                "description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-19T20:38:25.279Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/features.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b99f04ae3d200d2f8844aa29145bd18eccbeecde",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "d8312a56d9a162e3ec76476aa487e7d20bc602e9",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "44aae426dbfd51286f7eb601cfa14bc32164812a",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "860aaff72c8446fed5e576249e19952883a18885",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "89237c8fc15d8016a194076e648ccb57d75e65ae",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "4bd0da48fbc1dbef6774175129107fbbdd353e26",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
              "lessThan": "a18f80bf5359238c4f067d691b96af00286fdd89",
              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "b6366f048e0caff28af5335b7af2031266e1b06b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/features.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.1"
            },
            {
              "lessThan": "4.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.261",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.212",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.96",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "4.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT\n\nRT migration is done aggressively. When a CPU schedules out a high\npriority RT task for a lower priority task, it will look to see if there\u0027s\nany RT tasks that are waiting to run on another CPU that is of higher\npriority than the task this CPU is about to run. If it finds one, it will\npull that task over to the CPU and allow it to run there instead.\n\nNormally, this pulling is done by looking at the RT overloaded mask (rto)\nwhich contains all the CPUs in the scheduler domain with RT tasks that are\nwaiting to run due to a higher priority RT task currently running on their\nCPU. The CPU that is about to schedule a lower priority task will grab the\nrq lock of the overloaded CPU and move the RT task from that CPU\u0027s runqueue\nto the local one and schedule the higher priority RT task.\n\nThis caused issues when a lot of CPUs would schedule a lower priority task\nat the same time. They would all try to grab the same runqueue lock of\nthe CPU with the overloaded RT tasks. Only the first CPU that got in will\nget that task. All the others would wait until they got the runqueue lock\nand see there\u0027s nothing to pull and do nothing. On systems with lots of\nCPUs, this caused a large latency (up to 500us) which is beyond what\nPREEMPT_RT is to allow.\n\nThe solution to that was to create an RT_PUSH_IPI logic. When any CPU\nwanted to pull a task, instead of grabbing the runqueue lock of the\noverloaded CPU, it would start by sending an IPI to the overloaded CPU,\nand that IPI handler would have the CPU with the waiting RT task do a push\ninstead. Then that handler would send an IPI to the next CPU with\noverloaded RT tasks, and so on. Note, after the first CPU starts this\nprocess, if another CPU wanted to do a pull, it would see that the process\nhas already begun and would only increment a counter to have the IPIs\ncontinue again.\n\nThe RT_PUSH_IPI solved the latency problem with PREEMPT_RT but could cause\na new issue with non PREEMPT_RT. Namely, softirqs run in a threaded\ncontext on PREEMPT_RT but they can run in an interrupt context in non-RT.\n\nIf an IPI lands on a CPU that has just woken up multiple RT tasks and the\ncurrent CPU is running a non RT or a low priority RT task, instead of\ndoing a push, it would simply do a schedule on that CPU. But if a softirq\nwas also executing on this CPU, the schedule would need to wait until the\nsoftirq finished. Until then, the CPU would still be considered overloaded\nas there are RT tasks still waiting to run on it.\n\nA live lock occurred on a workload that was doing heavy networking traffic\non a large machine where the softirqs would run 500us out of 750us. And it\nwould also be waking up RT tasks, causing the RT pull logic to be\nconstantly executed.\n\nWhen a softirq triggered on a CPU with RT tasks queued but not running\nyet, and the other CPUs would see this CPU as being overloaded, they would\nsend an IPI over to it. The CPU would notice that the waiting RT tasks are\nof higher priority than the currently running task and simply schedule\nthat CPU instead. But because the softirq was executing, before it could\nschedule, it would receive another IPI to do the same. The amount of IPIs\nwould slow down the currently running softirq so much that before it could\nreturn back to task context, it would execute another softirq never\nallowing the CPU to schedule. This live locked that CPU.\n\nAs RT_PUSH_IPI was created to help PREEMPT_RT, make it default off if\nPREEMPT_RT is not enabled."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - Unauthenticated inbound network traffic can sustain NET_RX softirq processing and trigger the scheduler livelock on a vulnerable non-PREEMPT_RT SMP host with ordinary kernel RT threads.\nAC:L - Sustained traffic overlapping recurring RT-thread wakeups is sufficient; upstream observed reliable production lockups at only 30\u201340% CPU utilization, without a precise race win or memory-layout requirement.\nPR:N - The remote sender requires no account, capability, or protocol authentication because packet reception precedes such checks and the required RT tasks can be created by existing kernel drivers and system services.\nUI:N - No victim action is required once the affected host is running its normal workload; the attacker can maintain the triggering packet stream independently.\nS:U - The livelock affects availability within the vulnerable host kernel\u0027s existing security authority and does not cross a VM, sandbox, or hardware-isolation boundary.\nC:N - The defect causes an IPI scheduling loop without an out-of-bounds access, use-after-free, uninitialized read, or other information-disclosure mechanism.\nI:N - The vulnerable path does not corrupt memory or provide a write primitive, data modification, or control-flow influence.\nA:H - The repeated push IPIs can livelock a CPU, produce a soft lockup, indefinitely stall workloads, and potentially cause a watchdog panic or whole-host denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:54:24.413Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b99f04ae3d200d2f8844aa29145bd18eccbeecde"
        },
        {
          "url": "https://git.kernel.org/stable/c/d8312a56d9a162e3ec76476aa487e7d20bc602e9"
        },
        {
          "url": "https://git.kernel.org/stable/c/44aae426dbfd51286f7eb601cfa14bc32164812a"
        },
        {
          "url": "https://git.kernel.org/stable/c/860aaff72c8446fed5e576249e19952883a18885"
        },
        {
          "url": "https://git.kernel.org/stable/c/89237c8fc15d8016a194076e648ccb57d75e65ae"
        },
        {
          "url": "https://git.kernel.org/stable/c/4bd0da48fbc1dbef6774175129107fbbdd353e26"
        },
        {
          "url": "https://git.kernel.org/stable/c/a18f80bf5359238c4f067d691b96af00286fdd89"
        },
        {
          "url": "https://git.kernel.org/stable/c/dd29c017aed628076e915fe4cdfb5392fd4c5cab"
        }
      ],
      "title": "sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64374",
    "datePublished": "2026-07-25T08:50:26.130Z",
    "dateReserved": "2026-07-19T15:36:31.784Z",
    "dateUpdated": "2026-10-19T20:38:25.279Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

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