FKIE_CVE-2026-23002

Vulnerability from fkie_nvd - Published: 2026-01-25 15:15 - Updated: 2026-01-26 15:03
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: lib/buildid: use __kernel_read() for sleepable context Prevent a "BUG: unable to handle kernel NULL pointer dereference in filemap_read_folio". For the sleepable context, convert freader to use __kernel_read() instead of direct page cache access via read_cache_folio(). This simplifies the faultable code path by using the standard kernel file reading interface which handles all the complexity of reading file data. At the moment we are not changing the code for non-sleepable context which uses filemap_get_folio() and only succeeds if the target folios are already in memory and up-to-date. The reason is to keep the patch simple and easier to backport to stable kernels. Syzbot repro does not crash the kernel anymore and the selftests run successfully. In the follow up we will make __kernel_read() with IOCB_NOWAIT work for non-sleepable contexts. In addition, I would like to replace the secretmem check with a more generic approach and will add fstest for the buildid code.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/568aeb3476c770a3863c755dd2a199c212434286
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/777a8560fd29738350c5094d4166fe5499452409
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b11dfb7708f212b96c7973a474014c071aa02e05
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlib/buildid: use __kernel_read() for sleepable context\n\nPrevent a \"BUG: unable to handle kernel NULL pointer dereference in\nfilemap_read_folio\".\n\nFor the sleepable context, convert freader to use __kernel_read() instead\nof direct page cache access via read_cache_folio().  This simplifies the\nfaultable code path by using the standard kernel file reading interface\nwhich handles all the complexity of reading file data.\n\nAt the moment we are not changing the code for non-sleepable context which\nuses filemap_get_folio() and only succeeds if the target folios are\nalready in memory and up-to-date.  The reason is to keep the patch simple\nand easier to backport to stable kernels.\n\nSyzbot repro does not crash the kernel anymore and the selftests run\nsuccessfully.\n\nIn the follow up we will make __kernel_read() with IOCB_NOWAIT work for\nnon-sleepable contexts.  In addition, I would like to replace the\nsecretmem check with a more generic approach and will add fstest for the\nbuildid code."
    }
  ],
  "id": "CVE-2026-23002",
  "lastModified": "2026-01-26T15:03:33.357",
  "metrics": {},
  "published": "2026-01-25T15:15:55.070",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/568aeb3476c770a3863c755dd2a199c212434286"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/777a8560fd29738350c5094d4166fe5499452409"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b11dfb7708f212b96c7973a474014c071aa02e05"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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