gsd-2023-52597
Vulnerability from gsd
Modified
2024-03-03 06:01
Details
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: fix setting of fpc register kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control (fpc) register of a guest cpu. The new value is tested for validity by temporarily loading it into the fpc register. This may lead to corruption of the fpc register of the host process: if an interrupt happens while the value is temporarily loaded into the fpc register, and within interrupt context floating point or vector registers are used, the current fp/vx registers are saved with save_fpu_regs() assuming they belong to user space and will be loaded into fp/vx registers when returning to user space. test_fp_ctl() restores the original user space / host process fpc register value, however it will be discarded, when returning to user space. In result the host process will incorrectly continue to run with the value that was supposed to be used for a guest cpu. Fix this by simply removing the test. There is another test right before the SIE context is entered which will handles invalid values. This results in a change of behaviour: invalid values will now be accepted instead of that the ioctl fails with -EINVAL. This seems to be acceptable, given that this interface is most likely not used anymore, and this is in addition the same behaviour implemented with the memory mapped interface (replace invalid values with zero) - see sync_regs() in kvm-s390.c.
Aliases


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{
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2023-52597"
      ],
      "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: fix setting of fpc register\n\nkvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control\n(fpc) register of a guest cpu. The new value is tested for validity by\ntemporarily loading it into the fpc register.\n\nThis may lead to corruption of the fpc register of the host process:\nif an interrupt happens while the value is temporarily loaded into the fpc\nregister, and within interrupt context floating point or vector registers\nare used, the current fp/vx registers are saved with save_fpu_regs()\nassuming they belong to user space and will be loaded into fp/vx registers\nwhen returning to user space.\n\ntest_fp_ctl() restores the original user space / host process fpc register\nvalue, however it will be discarded, when returning to user space.\n\nIn result the host process will incorrectly continue to run with the value\nthat was supposed to be used for a guest cpu.\n\nFix this by simply removing the test. There is another test right before\nthe SIE context is entered which will handles invalid values.\n\nThis results in a change of behaviour: invalid values will now be accepted\ninstead of that the ioctl fails with -EINVAL. This seems to be acceptable,\ngiven that this interface is most likely not used anymore, and this is in\naddition the same behaviour implemented with the memory mapped interface\n(replace invalid values with zero) - see sync_regs() in kvm-s390.c.",
      "id": "GSD-2023-52597",
      "modified": "2024-03-03T06:01:51.647161Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
    "cve.org": {
      "CVE_data_meta": {
        "ASSIGNER": "cve@kernel.org",
        "ID": "CVE-2023-52597",
        "STATE": "PUBLIC"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "Linux",
                    "version": {
                      "version_data": [
                        {
                          "version_affected": "\u003c",
                          "version_name": "1da177e4c3f4",
                          "version_value": "3a04410b0bc7"
                        },
                        {
                          "version_value": "not down converted",
                          "x_cve_json_5_version_data": {
                            "defaultStatus": "affected",
                            "versions": [
                              {
                                "lessThanOrEqual": "4.19.*",
                                "status": "unaffected",
                                "version": "4.19.307",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "5.4.*",
                                "status": "unaffected",
                                "version": "5.4.269",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "5.10.*",
                                "status": "unaffected",
                                "version": "5.10.210",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "5.15.*",
                                "status": "unaffected",
                                "version": "5.15.149",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "6.1.*",
                                "status": "unaffected",
                                "version": "6.1.77",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "6.6.*",
                                "status": "unaffected",
                                "version": "6.6.16",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "6.7.*",
                                "status": "unaffected",
                                "version": "6.7.4",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "*",
                                "status": "unaffected",
                                "version": "6.8",
                                "versionType": "original_commit_for_fix"
                              }
                            ]
                          }
                        }
                      ]
                    }
                  }
                ]
              },
              "vendor_name": "Linux"
            }
          ]
        }
      },
      "data_format": "MITRE",
      "data_type": "CVE",
      "data_version": "4.0",
      "description": {
        "description_data": [
          {
            "lang": "eng",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: fix setting of fpc register\n\nkvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control\n(fpc) register of a guest cpu. The new value is tested for validity by\ntemporarily loading it into the fpc register.\n\nThis may lead to corruption of the fpc register of the host process:\nif an interrupt happens while the value is temporarily loaded into the fpc\nregister, and within interrupt context floating point or vector registers\nare used, the current fp/vx registers are saved with save_fpu_regs()\nassuming they belong to user space and will be loaded into fp/vx registers\nwhen returning to user space.\n\ntest_fp_ctl() restores the original user space / host process fpc register\nvalue, however it will be discarded, when returning to user space.\n\nIn result the host process will incorrectly continue to run with the value\nthat was supposed to be used for a guest cpu.\n\nFix this by simply removing the test. There is another test right before\nthe SIE context is entered which will handles invalid values.\n\nThis results in a change of behaviour: invalid values will now be accepted\ninstead of that the ioctl fails with -EINVAL. This seems to be acceptable,\ngiven that this interface is most likely not used anymore, and this is in\naddition the same behaviour implemented with the memory mapped interface\n(replace invalid values with zero) - see sync_regs() in kvm-s390.c."
          }
        ]
      },
      "generator": {
        "engine": "bippy-8df59b4913de"
      },
      "problemtype": {
        "problemtype_data": [
          {
            "description": [
              {
                "lang": "eng",
                "value": "n/a"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://git.kernel.org/stable/c/3a04410b0bc7e056e0843ac598825dd359246d18",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/3a04410b0bc7e056e0843ac598825dd359246d18"
          },
          {
            "name": "https://git.kernel.org/stable/c/5e63c9ae8055109d805aacdaf2a4fe2c3b371ba1",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/5e63c9ae8055109d805aacdaf2a4fe2c3b371ba1"
          },
          {
            "name": "https://git.kernel.org/stable/c/150a3a3871490e8c454ffbac2e60abeafcecff99",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/150a3a3871490e8c454ffbac2e60abeafcecff99"
          },
          {
            "name": "https://git.kernel.org/stable/c/732a3bea7aba5b15026ea42d14953c3425cc7dc2",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/732a3bea7aba5b15026ea42d14953c3425cc7dc2"
          },
          {
            "name": "https://git.kernel.org/stable/c/0671f42a9c1084db10d68ac347d08dbf6689ecb3",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/0671f42a9c1084db10d68ac347d08dbf6689ecb3"
          },
          {
            "name": "https://git.kernel.org/stable/c/c87d7d910775a025e230fd6359b60627e392460f",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/c87d7d910775a025e230fd6359b60627e392460f"
          },
          {
            "name": "https://git.kernel.org/stable/c/2823db0010c400e4b2b12d02aa5d0d3ecb15d7c7",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/2823db0010c400e4b2b12d02aa5d0d3ecb15d7c7"
          },
          {
            "name": "https://git.kernel.org/stable/c/b988b1bb0053c0dcd26187d29ef07566a565cf55",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/b988b1bb0053c0dcd26187d29ef07566a565cf55"
          }
        ]
      }
    },
    "nvd.nist.gov": {
      "cve": {
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: fix setting of fpc register\n\nkvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control\n(fpc) register of a guest cpu. The new value is tested for validity by\ntemporarily loading it into the fpc register.\n\nThis may lead to corruption of the fpc register of the host process:\nif an interrupt happens while the value is temporarily loaded into the fpc\nregister, and within interrupt context floating point or vector registers\nare used, the current fp/vx registers are saved with save_fpu_regs()\nassuming they belong to user space and will be loaded into fp/vx registers\nwhen returning to user space.\n\ntest_fp_ctl() restores the original user space / host process fpc register\nvalue, however it will be discarded, when returning to user space.\n\nIn result the host process will incorrectly continue to run with the value\nthat was supposed to be used for a guest cpu.\n\nFix this by simply removing the test. There is another test right before\nthe SIE context is entered which will handles invalid values.\n\nThis results in a change of behaviour: invalid values will now be accepted\ninstead of that the ioctl fails with -EINVAL. This seems to be acceptable,\ngiven that this interface is most likely not used anymore, and this is in\naddition the same behaviour implemented with the memory mapped interface\n(replace invalid values with zero) - see sync_regs() in kvm-s390.c."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: KVM: s390: configuraci\u00f3n fija del registro fpc kvm_arch_vcpu_ioctl_set_fpu() permite configurar el registro de control de punto flotante (fpc) de una CPU invitada. Se prueba la validez del nuevo valor carg\u00e1ndolo temporalmente en el registro fpc. Esto puede conducir a la corrupci\u00f3n del registro fpc del proceso host: si ocurre una interrupci\u00f3n mientras el valor se carga temporalmente en el registro fpc, y dentro del contexto de interrupci\u00f3n se utilizan registros de punto flotante o vectoriales, los registros fp/vx actuales se guardan con save_fpu_regs() suponiendo que pertenecen al espacio del usuario y se cargar\u00e1n en los registros fp/vx cuando regresen al espacio del usuario. test_fp_ctl() restaura el valor de registro fpc del proceso de host/espacio de usuario original; sin embargo, se descartar\u00e1 al regresar al espacio de usuario. Como resultado, el proceso del host continuar\u00e1 ejecut\u00e1ndose incorrectamente con el valor que se supon\u00eda que deb\u00eda usarse para una CPU invitada. Solucione este problema simplemente quitando la prueba. Hay otra prueba justo antes de ingresar al contexto SIE que manejar\u00e1 valores no v\u00e1lidos. Esto da como resultado un cambio de comportamiento: ahora se aceptar\u00e1n valores no v\u00e1lidos en lugar de que el ioctl falle con -EINVAL. Esto parece aceptable, dado que lo m\u00e1s probable es que esta interfaz ya no se use y, adem\u00e1s, este es el mismo comportamiento implementado con la interfaz asignada en memoria (reemplace los valores no v\u00e1lidos con cero); consulte sync_regs() en kvm-s390.c."
          }
        ],
        "id": "CVE-2023-52597",
        "lastModified": "2024-03-06T15:18:08.093",
        "metrics": {},
        "published": "2024-03-06T07:15:09.827",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/0671f42a9c1084db10d68ac347d08dbf6689ecb3"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/150a3a3871490e8c454ffbac2e60abeafcecff99"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/2823db0010c400e4b2b12d02aa5d0d3ecb15d7c7"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/3a04410b0bc7e056e0843ac598825dd359246d18"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/5e63c9ae8055109d805aacdaf2a4fe2c3b371ba1"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/732a3bea7aba5b15026ea42d14953c3425cc7dc2"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/b988b1bb0053c0dcd26187d29ef07566a565cf55"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c87d7d910775a025e230fd6359b60627e392460f"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Awaiting Analysis"
      }
    }
  }
}


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