← Back to CVE Explorer

CVE-2025-39813

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix potential warning in trace_printk_seq during ftrace_dump When calling ftrace_dump_one() concurrently with reading trace_pipe, a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race condition. The issue occurs because: CPU0 (ftrace_dump) CPU1 (reader) echo z > /proc/sysrq-trigger !trace_empty(&iter) trace_iterator_reset(&iter) <- len = size = 0 cat /sys/kernel/tracing/trace_pipe trace_find_next_entry_inc(&iter) __find_next_entry ring_buffer_empty_cpu <- all empty return NULL trace_printk_seq(&iter.seq) WARN_ON_ONCE(s->seq.len >= s->seq.size) In the context between trace_empty() and trace_find_next_entry_inc() during ftrace_dump, the ring buffer data was consumed by other readers. This caused trace_find_next_entry_inc to return NULL, failing to populate `iter.seq`. At this point, due to the prior trace_iterator_reset, both `iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal, the WARN_ON_ONCE condition is triggered. Move the trace_printk_seq() into the if block that checks to make sure the return value of trace_find_next_entry_inc() is non-NULL in ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before subsequent operations.

Severity
MEDIUM
CVSS score
4.7 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-09-16 13:15:55.150000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON 
{
  "id": "CVE-2025-39813",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-09-16T13:15:55.150",
  "lastModified": "2026-10-19T21:10:00.160",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nftrace: Fix potential warning in trace_printk_seq during ftrace_dump\n\nWhen calling ftrace_dump_one() concurrently with reading trace_pipe,\na WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race\ncondition.\n\nThe issue occurs because:\n\nCPU0 (ftrace_dump)                              CPU1 (reader)\necho z > /proc/sysrq-trigger\n\n!trace_empty(&iter)\ntrace_iterator_reset(&iter) <- len = size = 0\n                                                cat /sys/kernel/tracing/trace_pipe\ntrace_find_next_entry_inc(&iter)\n  __find_next_entry\n    ring_buffer_empty_cpu <- all empty\n  return NULL\n\ntrace_printk_seq(&iter.seq)\n  WARN_ON_ONCE(s->seq.len >= s->seq.size)\n\nIn the context between trace_empty() and trace_find_next_entry_inc()\nduring ftrace_dump, the ring buffer data was consumed by other readers.\nThis caused trace_find_next_entry_inc to return NULL, failing to populate\n`iter.seq`. At this point, due to the prior trace_iterator_reset, both\n`iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal,\nthe WARN_ON_ONCE condition is triggered.\n\nMove the trace_printk_seq() into the if block that checks to make sure the\nreturn value of trace_find_next_entry_inc() is non-NULL in\nftrace_dump_one(), ensuring the 'iter.seq' is properly populated before\nsubsequent operations."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nftrace: Soluciona una advertencia potencial en trace_printk_seq durante ftrace_dump\n\nAl llamar a ftrace_dump_one() concurrentemente con la lectura de trace_pipe, una WARN_ON_ONCE() en trace_printk_seq() puede ser activada debido a una condición de carrera.\n\nEl problema ocurre porque:\n\nCPU0 (ftrace_dump)                              CPU1 (lector)\necho z > /proc/sysrq-trigger\n\n!trace_empty(&iter)\ntrace_iterator_reset(&iter) <- len = size = 0\n                                                cat /sys/kernel/tracing/trace_pipe\ntrace_find_next_entry_inc(&iter)\n  __find_next_entry\n    ring_buffer_empty_cpu <- todo vacío\n  return NULL\n\ntrace_printk_seq(&iter.seq)\n  WARN_ON_ONCE(s->seq.len >= s->seq.size)\n\nEn el contexto entre trace_empty() y trace_find_next_entry_inc() durante ftrace_dump, los datos del búfer circular fueron consumidos por otros lectores. Esto hizo que trace_find_next_entry_inc devolviera NULL, fallando en poblar 'iter.seq'. En este punto, debido al trace_iterator_reset previo, tanto 'iter.seq.len' como 'iter.seq.size' se establecieron en 0. Dado que son iguales, la condición WARN_ON_ONCE se activa.\n\nMover trace_printk_seq() al bloque 'if' que verifica que el valor de retorno de trace_find_next_entry_inc() no sea NULL en ftrace_dump_one(), asegurando que 'iter.seq' se pueble correctamente antes de operaciones posteriores."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/trace/trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "f299353e7ccbcc5c2ed8993c48fbe7609cbe729a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "5ab0ec206deb99eb3baf8f1d7602aeaa91dbcc85",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "a6f0f8873cc30fd4543b09adf03f7f51d293f0e6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "e80ff23ba8bdb0f41a1afe2657078e4097d13a9a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "28c8fb7ae2ad27d81c8de3c4fe608c509f6a18aa",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "ced94e137e6cd5e79c65564841d3b7695d0f5fa3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "fbd4cf7ee4db65ef36796769fe978e9eba6f0de4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d769041f865330034131525ee6a7f72eb4af2a24",
              "lessThan": "4013aef2ced9b756a410f50d12df9ebe6a883e4a",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/trace/trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "2.6.28",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "2.6.28",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.4.298",
              "lessThanOrEqual": "5.4.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.242",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.191",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.150",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.104",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.45",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.16.5",
              "lessThanOrEqual": "6.16.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.17",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    },
    {
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
      "affectedData": [
        {
          "vendor": "Siemens",
          "product": "SIMATIC CN 4100",
          "defaultStatus": "unknown",
          "versions": [
            {
              "version": "0",
              "lessThan": "V5.0",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "2.6.28",
              "versionEndExcluding": "5.4.298",
              "matchCriteriaId": "FAC85C88-8EB4-481B-BAFD-B69CEBEFC6AA"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.5",
              "versionEndExcluding": "5.10.242",
              "matchCriteriaId": "CFAE7D1D-31D7-4259-8581-3CB64D12DE3B"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.11",
              "versionEndExcluding": "5.15.191",
              "matchCriteriaId": "A532F1D1-B7A9-4745-AB0E-B6AD12CAD0BD"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.16",
              "versionEndExcluding": "6.1.150",
              "matchCriteriaId": "67AC87D5-97BF-4617-92EF-9E282B6D1CF7"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.2",
              "versionEndExcluding": "6.6.104",
              "matchCriteriaId": "FD12E3C3-F737-4936-9A57-80832E36D22F"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.7",
              "versionEndExcluding": "6.12.45",
              "matchCriteriaId": "DC443D7D-A411-41FB-BB45-010F36EF7C94"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.13",
              "versionEndExcluding": "6.16.5",
              "matchCriteriaId": "EB781080-7001-4FA1-B388-517FFEFBC73E"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"
            }
          ]
        }
      ]
    },
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/28c8fb7ae2ad27d81c8de3c4fe608c509f6a18aa",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/4013aef2ced9b756a410f50d12df9ebe6a883e4a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/5ab0ec206deb99eb3baf8f1d7602aeaa91dbcc85",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/a6f0f8873cc30fd4543b09adf03f7f51d293f0e6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/ced94e137e6cd5e79c65564841d3b7695d0f5fa3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/e80ff23ba8bdb0f41a1afe2657078e4097d13a9a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/f299353e7ccbcc5c2ed8993c48fbe7609cbe729a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/fbd4cf7ee4db65ef36796769fe978e9eba6f0de4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html",
      "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
    }
  ]
}