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FKIE_CVE-2026-23383

Vulnerability from fkie_nvd - Published: 2026-03-25 11:16 - Updated: 2026-06-17 10:21
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing struct bpf_plt contains a u64 target field. Currently, the BPF JIT allocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT buffer. Because the base address of the JIT buffer can be 4-byte aligned (e.g., ending in 0x4 or 0xc), the relative padding logic in build_plt() fails to ensure that target lands on an 8-byte boundary. This leads to two issues: 1. UBSAN reports misaligned-access warnings when dereferencing the structure. 2. More critically, target is updated concurrently via WRITE_ONCE() in bpf_arch_text_poke() while the JIT'd code executes ldr. On arm64, 64-bit loads/stores are only guaranteed to be single-copy atomic if they are 64-bit aligned. A misaligned target risks a torn read, causing the JIT to jump to a corrupted address. Fix this by increasing the allocation alignment requirement to 8 bytes (sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of the JIT buffer to an 8-byte boundary, allowing the relative padding math in build_plt() to correctly align the target field.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1dePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dcPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 6.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/net/bpf_jit_comp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "80ad264da02cc4aee718e799c2b79f0f834673dc",
              "status": "affected",
              "version": "b2ad54e1533e91449cb2a371e034942bd7882b58",
              "versionType": "git"
            },
            {
              "lessThan": "519b1ad91de5bf7a496f2b858e9212db6328e1de",
              "status": "affected",
              "version": "b2ad54e1533e91449cb2a371e034942bd7882b58",
              "versionType": "git"
            },
            {
              "lessThan": "66959ed481a474eaae278c7f6860a2a9b188a4d6",
              "status": "affected",
              "version": "b2ad54e1533e91449cb2a371e034942bd7882b58",
              "versionType": "git"
            },
            {
              "lessThan": "ef06fd16d48704eac868441d98d4ef083d8f3d07",
              "status": "affected",
              "version": "b2ad54e1533e91449cb2a371e034942bd7882b58",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/net/bpf_jit_comp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.77",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5D973B34-246F-4A22-882C-BBD5EB00997D",
              "versionEndExcluding": "6.12.77",
              "versionStartIncluding": "6.0.1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A5E006E4-59C7-43C1-9231-62A72219F2BA",
              "versionEndExcluding": "6.18.17",
              "versionStartIncluding": "6.13",
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            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "versionEndExcluding": "6.19.7",
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            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.0:-:*:*:*:*:*:*",
              "matchCriteriaId": "7BE551E5-89CF-47A8-9B26-03CE727FBA37",
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              "vulnerable": true
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              "vulnerable": true
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          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing\n\nstruct bpf_plt contains a u64 target field. Currently, the BPF JIT\nallocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT\nbuffer.\n\nBecause the base address of the JIT buffer can be 4-byte aligned (e.g.,\nending in 0x4 or 0xc), the relative padding logic in build_plt() fails\nto ensure that target lands on an 8-byte boundary.\n\nThis leads to two issues:\n1. UBSAN reports misaligned-access warnings when dereferencing the\n   structure.\n2. More critically, target is updated concurrently via WRITE_ONCE() in\n   bpf_arch_text_poke() while the JIT\u0027d code executes ldr. On arm64,\n   64-bit loads/stores are only guaranteed to be single-copy atomic if\n   they are 64-bit aligned. A misaligned target risks a torn read,\n   causing the JIT to jump to a corrupted address.\n\nFix this by increasing the allocation alignment requirement to 8 bytes\n(sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of\nthe JIT buffer to an 8-byte boundary, allowing the relative padding math\nin build_plt() to correctly align the target field."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nbpf, arm64: Forzar alineaci\u00f3n de 8 bytes para el b\u00fafer JIT para prevenir el desgarro at\u00f3mico\n\nstruct bpf_plt contiene un campo objetivo u64. Actualmente, el asignador JIT de BPF solicita una alineaci\u00f3n de 4 bytes (sizeof(u32)) para el b\u00fafer JIT.\n\nDebido a que la direcci\u00f3n base del b\u00fafer JIT puede estar alineada a 4 bytes (p. ej., terminando en 0x4 o 0xc), la l\u00f3gica de relleno relativo en build_plt() no logra asegurar que target caiga en un l\u00edmite de 8 bytes.\n\nEsto lleva a dos problemas:\n1. UBSAN informa advertencias de acceso desalineado al desreferenciar la estructura.\n2. M\u00e1s cr\u00edticamente, target se actualiza concurrentemente a trav\u00e9s de WRITE_ONCE() en bpf_arch_text_poke() mientras el c\u00f3digo JIT\u0027d ejecuta ldr. En arm64, las cargas/almacenamientos de 64 bits solo se garantiza que sean at\u00f3micos de copia \u00fanica si est\u00e1n alineados a 64 bits. Un target desalineado arriesga una lectura desgarrada, haciendo que el JIT salte a una direcci\u00f3n corrupta.\n\nSolucione esto aumentando el requisito de alineaci\u00f3n de asignaci\u00f3n a 8 bytes (sizeof(u64)) en bpf_jit_binary_pack_alloc(). Esto ancla la base del b\u00fafer JIT a un l\u00edmite de 8 bytes, permitiendo que las matem\u00e1ticas de relleno relativo en build_plt() alineen correctamente el campo target."
    }
  ],
  "id": "CVE-2026-23383",
  "lastModified": "2026-06-17T10:21:28.433",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-03-25T11:16:38.487",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1de"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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