FKIE_CVE-2026-64082

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:17
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: riscv: Fix register corruption from uninitialized cregs on error compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/kernel/compat_signal.c",
            "arch/riscv/kernel/ptrace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9e020156833f1ad0d425a1e3d85b65639f1c1c50",
              "status": "affected",
              "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea",
              "versionType": "git"
            },
            {
              "lessThan": "6ebcbb53fc9bc30843054ed99fd60b8e542628f4",
              "status": "affected",
              "version": "7383ee05314be58f8f9f018ee0ac53bef3808aea",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/kernel/compat_signal.c",
            "arch/riscv/kernel/ptrace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: Fix register corruption from uninitialized cregs on error\n\ncompat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when\nuser_regset_copyin() fails. Since cregs is an uninitialized stack\nvariable, a copyin failure causes uninitialized stack data to be written\ninto the target task\u0027s pt_regs, corrupting its register state and\npotentially leaking kernel stack contents.\n\ncompat_restore_sigcontext() has the same issue: it calls cregs_to_regs()\neven when __copy_from_user() fails, leading to the same corruption of\nthe signal-returning task\u0027s register state on error.\n\nOnly call cregs_to_regs() when the user copy succeeds."
    }
  ],
  "id": "CVE-2026-64082",
  "lastModified": "2026-07-20T15:17:07.663",
  "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": "2026-07-19T16:17:48.807",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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