FKIE_CVE-2022-50425

Vulnerability from fkie_nvd - Published: 2025-10-01 12:15 - Updated: 2026-01-20 20:14
Severity ?
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly When an extended state component is not present in fpstate, but in init state, the function copies from init_fpstate via copy_feature(). But, dynamic states are not present in init_fpstate because of all-zeros init states. Then retrieving them from init_fpstate will explode like this: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:memcpy_erms+0x6/0x10 ? __copy_xstate_to_uabi_buf+0x381/0x870 fpu_copy_guest_fpstate_to_uabi+0x28/0x80 kvm_arch_vcpu_ioctl+0x14c/0x1460 [kvm] ? __this_cpu_preempt_check+0x13/0x20 ? vmx_vcpu_put+0x2e/0x260 [kvm_intel] kvm_vcpu_ioctl+0xea/0x6b0 [kvm] ? kvm_vcpu_ioctl+0xea/0x6b0 [kvm] ? __fget_light+0xd4/0x130 __x64_sys_ioctl+0xe3/0x910 ? debug_smp_processor_id+0x17/0x20 ? fpregs_assert_state_consistent+0x27/0x50 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Adjust the 'mask' to zero out the userspace buffer for the features that are not available both from fpstate and from init_fpstate. The dynamic features depend on the compacted XSAVE format. Ensure it is enabled before reading XCOMP_BV in init_fpstate.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/471f0aa7fa64e23766a1473b32d9ec3f0718895aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6ff29642fd28965a8f8d6d326ac91bf6075f3113Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel 6.1
To clipboard 

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  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "65D387F0-209C-4EAD-98BA-C4B430A840C9",
              "versionEndExcluding": "6.0.7",
              "versionStartIncluding": "5.16",
              "vulnerable": true
            },
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              "criteria": "cpe:2.3:o:linux:linux_kernel:6.1:rc1:*:*:*:*:*:*",
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly\n\nWhen an extended state component is not present in fpstate, but in init\nstate, the function copies from init_fpstate via copy_feature().\n\nBut, dynamic states are not present in init_fpstate because of all-zeros\ninit states. Then retrieving them from init_fpstate will explode like this:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n ...\n RIP: 0010:memcpy_erms+0x6/0x10\n  ? __copy_xstate_to_uabi_buf+0x381/0x870\n  fpu_copy_guest_fpstate_to_uabi+0x28/0x80\n  kvm_arch_vcpu_ioctl+0x14c/0x1460 [kvm]\n  ? __this_cpu_preempt_check+0x13/0x20\n  ? vmx_vcpu_put+0x2e/0x260 [kvm_intel]\n  kvm_vcpu_ioctl+0xea/0x6b0 [kvm]\n  ? kvm_vcpu_ioctl+0xea/0x6b0 [kvm]\n  ? __fget_light+0xd4/0x130\n  __x64_sys_ioctl+0xe3/0x910\n  ? debug_smp_processor_id+0x17/0x20\n  ? fpregs_assert_state_consistent+0x27/0x50\n  do_syscall_64+0x3f/0x90\n  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nAdjust the \u0027mask\u0027 to zero out the userspace buffer for the features that\nare not available both from fpstate and from init_fpstate.\n\nThe dynamic features depend on the compacted XSAVE format. Ensure it is\nenabled before reading XCOMP_BV in init_fpstate."
    }
  ],
  "id": "CVE-2022-50425",
  "lastModified": "2026-01-20T20:14:12.247",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-10-01T12:15:33.987",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/471f0aa7fa64e23766a1473b32d9ec3f0718895a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/6ff29642fd28965a8f8d6d326ac91bf6075f3113"
    }
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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