CVE-2025-40327 (GCVE-0-2025-40327)
Vulnerability from cvelistv5
Published
2025-12-09 04:09
Modified
2025-12-09 04:09
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix system hang caused by cpu-clock usage cpu-clock usage by the async-profiler tool can trigger a system hang, which got bisected back to the following commit by Octavia Togami: 18dbcbfabfff ("perf: Fix the POLL_HUP delivery breakage") causes this issue The root cause of the hang is that cpu-clock is a special type of SW event which relies on hrtimers. The __perf_event_overflow() callback is invoked from the hrtimer handler for cpu-clock events, and __perf_event_overflow() tries to call cpu_clock_event_stop() to stop the event, which calls htimer_cancel() to cancel the hrtimer. But that's a recursion into the hrtimer code from a hrtimer handler, which (unsurprisingly) deadlocks. To fix this bug, use hrtimer_try_to_cancel() instead, and set the PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer() to stop the event once it sees the PERF_HES_STOPPED flag. [ mingo: Fixed the comments and improved the changelog. ]
References
Impacted products
Vendor Product Version
Linux Linux Version: 18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240
Version: 18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240
Version: b2de0c9ce8e542b5cb4cd3944620d9dd1ea1f0ac
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6b8c512811644cf2f5eaf6f44e928683c54127f0",
              "status": "affected",
              "version": "18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240",
              "versionType": "git"
            },
            {
              "lessThan": "eb3182ef0405ff2f6668fd3e5ff9883f60ce8801",
              "status": "affected",
              "version": "18dbcbfabfffc4a5d3ea10290c5ad27f22b0d240",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b2de0c9ce8e542b5cb4cd3944620d9dd1ea1f0ac",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.8",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.16.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf/core: Fix system hang caused by cpu-clock usage\n\ncpu-clock usage by the async-profiler tool can trigger a system hang,\nwhich got bisected back to the following commit by Octavia Togami:\n\n  18dbcbfabfff (\"perf: Fix the POLL_HUP delivery breakage\") causes this issue\n\nThe root cause of the hang is that cpu-clock is a special type of SW\nevent which relies on hrtimers. The __perf_event_overflow() callback\nis invoked from the hrtimer handler for cpu-clock events, and\n__perf_event_overflow() tries to call cpu_clock_event_stop()\nto stop the event, which calls htimer_cancel() to cancel the hrtimer.\n\nBut that\u0027s a recursion into the hrtimer code from a hrtimer handler,\nwhich (unsurprisingly) deadlocks.\n\nTo fix this bug, use hrtimer_try_to_cancel() instead, and set\nthe PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer()\nto stop the event once it sees the PERF_HES_STOPPED flag.\n\n[ mingo: Fixed the comments and improved the changelog. ]"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-09T04:09:43.522Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6b8c512811644cf2f5eaf6f44e928683c54127f0"
        },
        {
          "url": "https://git.kernel.org/stable/c/eb3182ef0405ff2f6668fd3e5ff9883f60ce8801"
        }
      ],
      "title": "perf/core: Fix system hang caused by cpu-clock usage",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40327",
    "datePublished": "2025-12-09T04:09:43.522Z",
    "dateReserved": "2025-04-16T07:20:57.186Z",
    "dateUpdated": "2025-12-09T04:09:43.522Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-40327\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-12-09T16:17:42.787\",\"lastModified\":\"2025-12-09T18:37:13.640\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nperf/core: Fix system hang caused by cpu-clock usage\\n\\ncpu-clock usage by the async-profiler tool can trigger a system hang,\\nwhich got bisected back to the following commit by Octavia Togami:\\n\\n  18dbcbfabfff (\\\"perf: Fix the POLL_HUP delivery breakage\\\") causes this issue\\n\\nThe root cause of the hang is that cpu-clock is a special type of SW\\nevent which relies on hrtimers. The __perf_event_overflow() callback\\nis invoked from the hrtimer handler for cpu-clock events, and\\n__perf_event_overflow() tries to call cpu_clock_event_stop()\\nto stop the event, which calls htimer_cancel() to cancel the hrtimer.\\n\\nBut that\u0027s a recursion into the hrtimer code from a hrtimer handler,\\nwhich (unsurprisingly) deadlocks.\\n\\nTo fix this bug, use hrtimer_try_to_cancel() instead, and set\\nthe PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer()\\nto stop the event once it sees the PERF_HES_STOPPED flag.\\n\\n[ mingo: Fixed the comments and improved the changelog. ]\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/6b8c512811644cf2f5eaf6f44e928683c54127f0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/eb3182ef0405ff2f6668fd3e5ff9883f60ce8801\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.