UnratedFix available

w1: therm: Fix off-by-one buffer overflow in alarms_store

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: w1: therm: Fix off-by-one buffer overflow in alarms_store The sysfs buffer passed to alarms_store() is allocated with 'size + 1' bytes and a NUL terminator is appended. However, the 'size' argument does not account for this extra byte. The original code then allocated 'size' bytes and used strcpy() to copy 'buf', which always writes one byte past the allocated buffer since strcpy() copies until the NUL terminator at index 'size'. Fix this by parsing the 'buf' parameter directly using simple_strtoll() without allocating any intermediate memory or string copying. This removes the overflow while simplifying the code.

Products: Kernel
Affected versions: Not specified
Fixed versions: 5.10.249, 5.15.199, 6.1.162, 6.12.68, 6.18.8, 6.6.122
CVEs: CVE-2025-71197
Confirmed fixed CVEs: Not specified
Updated in this feed: 4 Nov 2026, 16:12 UTC · Revision 1

Source evidence

w1: therm: Fix off-by-one buffer overflow in alarms_store

core-osv · Original source

Published 4 Feb 2026, 16:07 UTC

osv:CVE-2025-71197

Kernel

Fixed versions: 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8

Complete source record

{
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  "url": "https://osv.dev/vulnerability/CVE-2025-71197",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "w1: therm: Fix off-by-one buffer overflow in alarms_store",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: w1: therm: Fix off-by-one buffer overflow in alarms_store The sysfs buffer passed to alarms_store() is allocated with 'size + 1' bytes and a NUL terminator is appended. However, the 'size' argument does not account for this extra byte. The original code then allocated 'size' bytes and used strcpy() to copy 'buf', which always writes one byte past the allocated buffer since strcpy() copies until the NUL terminator at index 'size'. Fix this by parsing the 'buf' parameter directly using simple_strtoll() without allocating any intermediate memory or string copying. This removes the overflow while simplifying the code.",
    "evidence": "osv:CVE-2025-71197",
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            "evidence": "/affected/1/ranges"
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    "severity": "unknown",
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      ],
      "modified": "2026-10-28T02:30:37.594692879Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
        "https://git.kernel.org/stable/c/060b08d72a38b158a7f850d4b83c17c2969e0f6b",
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      "provider_metadata": {
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    "related_cves": [
      {
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504520,
  "published_at": "2026-02-04T16:07:32.198+00:00"
}