Vulnerability-Lookup

GHSA-87CJ-725F-6HR5

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31

Details

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.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64082"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:48Z",
    "severity": "HIGH"
  },
  "details": "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": "GHSA-87cj-725f-6hr5",
  "modified": "2026-07-20T15:31:58Z",
  "published": "2026-07-19T18:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64082"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64082 (GCVE-0-2026-64082)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:43

Title

riscv: Fix register corruption from uninitialized cregs on error

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.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

2 references

URL	Tags
https://git.kernel.org/stable/c/9e020156833f1ad0d…
https://git.kernel.org/stable/c/6ebcbb53fc9bc3084…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7383ee05314be58f8f9f018ee0ac53bef3808aea , < 9e020156833f1ad0d425a1e3d85b65639f1c1c50 (git) Affected: 7383ee05314be58f8f9f018ee0ac53bef3808aea , < 6ebcbb53fc9bc30843054ed99fd60b8e542628f4 (git)
Linux	Linux	Affected: 5.19 Unaffected: 0 , < 5.19 (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
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        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "arch/riscv/kernel/compat_signal.c",
            "arch/riscv/kernel/ptrace.c"
          ],
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          "versions": [
            {
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              "versionType": "git"
            },
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              "lessThan": "6ebcbb53fc9bc30843054ed99fd60b8e542628f4",
              "status": "affected",
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              "versionType": "git"
            }
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        },
        {
          "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": [
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            },
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              "version": "0",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
                },
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                }
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        }
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      "metrics": [
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
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    "datePublished": "2026-07-19T15:39:54.074Z",
    "dateReserved": "2026-07-19T07:54:57.031Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-87CJ-725F-6HR5

CVE-2026-64082 (GCVE-0-2026-64082)

Tags

Sightings

Nomenclature