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CVE-2025-38710

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: gfs2: Validate i_depth for exhash directories A fuzzer test introduced corruption that ends up with a depth of 0 in dir_e_read(), causing an undefined shift by 32 at: index = hash >> (32 - dip->i_depth); As calculated in an open-coded way in dir_make_exhash(), the minimum depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time. So we can avoid the undefined behaviour by checking for depth values lower than the minimum in gfs2_dinode_in(). Values greater than the maximum are already being checked for there. Also switch the calculation in dir_make_exhash() to use ilog2() to clarify how the depth is calculated. Tested with the syzkaller repro.c and xfstests '-g quick'.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-09-04 16:15:40.137000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON 
{
  "id": "CVE-2025-38710",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-09-04T16:15:40.137",
  "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\ngfs2: Validate i_depth for exhash directories\n\nA fuzzer test introduced corruption that ends up with a depth of 0 in\ndir_e_read(), causing an undefined shift by 32 at:\n\n  index = hash >> (32 - dip->i_depth);\n\nAs calculated in an open-coded way in dir_make_exhash(), the minimum\ndepth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is\ninvalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time.\n\nSo we can avoid the undefined behaviour by checking for depth values\nlower than the minimum in gfs2_dinode_in(). Values greater than the\nmaximum are already being checked for there.\n\nAlso switch the calculation in dir_make_exhash() to use ilog2() to\nclarify how the depth is calculated.\n\nTested with the syzkaller repro.c and xfstests '-g quick'."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:\n\ngfs2: Validar i_depth para directorios exhash\n\nUna prueba de fuzzer introdujo corrupción que resulta en una profundidad de 0 en dir_e_read(), causando un desplazamiento indefinido de 32 en:\n\nindex = hash >> (32 - dip->i_depth);\n\nSegún se calcula de forma abierta en dir_make_exhash(), la profundidad mínima para un directorio exhash es ilog2(sdp->sd_hash_ptrs) y 0 no es válido ya que sdp->sd_hash_ptrs se fija como sdp->bsize / 16 en el momento del montaje.\n\nAsí podemos evitar el comportamiento indefinido comprobando los valores de profundidad inferiores al mínimo en gfs2_dinode_in(). Los valores mayores que el máximo ya se están comprobando allí.\n\nTambién cambiar el cálculo en dir_make_exhash() para usar ilog2() para clarificar cómo se calcula la profundidad.\n\nProbado con syzkaller repro.c y xfstests '-g quick'."
    }
  ],
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              "status": "unaffected"
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              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
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          "scope": "UNCHANGED",
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  "weaknesses": [
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      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
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