CVE-2021-47641 (GCVE-0-2021-47641)

Vulnerability from cvelistv5 – Published: 2025-02-26 01:54 – Updated: 2026-05-11 13:58
VLAI
Title
video: fbdev: cirrusfb: check pixclock to avoid divide by zero
Summary
In the Linux kernel, the following vulnerability has been resolved: video: fbdev: cirrusfb: check pixclock to avoid divide by zero Do a sanity check on pixclock value to avoid divide by zero. If the pixclock value is zero, the cirrusfb driver will round up pixclock to get the derived frequency as close to maxclock as possible. Syzkaller reported a divide error in cirrusfb_check_pixclock. divide error: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2 RIP: 0010:cirrusfb_check_var+0x6f1/0x1260 Call Trace: fb_set_var+0x398/0xf90 do_fb_ioctl+0x4b8/0x6f0 fb_ioctl+0xeb/0x130 __x64_sys_ioctl+0x19d/0x220 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-10-01 19:50 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c656d04247a2654ede5cead2ecbf83431dad5261 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 40b13e3d85744210db13457785646634e2d056bd (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 53a2088a396cfa1da92690a1da289634cd73bf0d (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 8c7e2141fb89c620ab4e41512e262fbf25b8260d (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 6fe23ff94e7840097202e85c148688940b37c9b1 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 45800c42ef000f417270bcfc08630e42486fca99 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < e498b504f8c81b07efab9febf8503448de4dc9cf (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 5c6f402bdcf9e7239c6bc7087eda71ac99b31379 (git)
Create a notification for this product.
Linux Linux Affected: 2.6.12
Unaffected: 0 , < 2.6.12 (semver)
Unaffected: 4.9.311 , ≤ 4.9.* (semver)
Unaffected: 4.14.276 , ≤ 4.14.* (semver)
Unaffected: 4.19.238 , ≤ 4.19.* (semver)
Unaffected: 5.4.189 , ≤ 5.4.* (semver)
Unaffected: 5.10.110 , ≤ 5.10.* (semver)
Unaffected: 5.15.33 , ≤ 5.15.* (semver)
Unaffected: 5.16.19 , ≤ 5.16.* (semver)
Unaffected: 5.17.2 , ≤ 5.17.* (semver)
Unaffected: 5.18 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "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"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-47641",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-10-01T19:50:40.514584Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-369",
                "description": "CWE-369 Divide By Zero",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-01T19:57:08.118Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/cirrusfb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c656d04247a2654ede5cead2ecbf83431dad5261",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "40b13e3d85744210db13457785646634e2d056bd",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "53a2088a396cfa1da92690a1da289634cd73bf0d",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "8c7e2141fb89c620ab4e41512e262fbf25b8260d",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6fe23ff94e7840097202e85c148688940b37c9b1",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "45800c42ef000f417270bcfc08630e42486fca99",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "e498b504f8c81b07efab9febf8503448de4dc9cf",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "5c6f402bdcf9e7239c6bc7087eda71ac99b31379",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/cirrusfb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.9.*",
              "status": "unaffected",
              "version": "4.9.311",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.14.*",
              "status": "unaffected",
              "version": "4.14.276",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.19.*",
              "status": "unaffected",
              "version": "4.19.238",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.16.*",
              "status": "unaffected",
              "version": "5.16.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.17.*",
              "status": "unaffected",
              "version": "5.17.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.9.311",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.14.276",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.19.238",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.189",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.110",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.33",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.16.19",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.17.2",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.18",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvideo: fbdev: cirrusfb: check pixclock to avoid divide by zero\n\nDo a sanity check on pixclock value to avoid divide by zero.\n\nIf the pixclock value is zero, the cirrusfb driver will round up\npixclock to get the derived frequency as close to maxclock as\npossible.\n\nSyzkaller reported a divide error in cirrusfb_check_pixclock.\n\ndivide error: 0000 [#1] SMP KASAN PTI\nCPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2\nRIP: 0010:cirrusfb_check_var+0x6f1/0x1260\n\nCall Trace:\n fb_set_var+0x398/0xf90\n do_fb_ioctl+0x4b8/0x6f0\n fb_ioctl+0xeb/0x130\n __x64_sys_ioctl+0x19d/0x220\n do_syscall_64+0x3a/0x80\n entry_SYSCALL_64_after_hwframe+0x44/0xae"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T13:58:19.521Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c656d04247a2654ede5cead2ecbf83431dad5261"
        },
        {
          "url": "https://git.kernel.org/stable/c/1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135"
        },
        {
          "url": "https://git.kernel.org/stable/c/40b13e3d85744210db13457785646634e2d056bd"
        },
        {
          "url": "https://git.kernel.org/stable/c/53a2088a396cfa1da92690a1da289634cd73bf0d"
        },
        {
          "url": "https://git.kernel.org/stable/c/8c7e2141fb89c620ab4e41512e262fbf25b8260d"
        },
        {
          "url": "https://git.kernel.org/stable/c/6fe23ff94e7840097202e85c148688940b37c9b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/45800c42ef000f417270bcfc08630e42486fca99"
        },
        {
          "url": "https://git.kernel.org/stable/c/e498b504f8c81b07efab9febf8503448de4dc9cf"
        },
        {
          "url": "https://git.kernel.org/stable/c/5c6f402bdcf9e7239c6bc7087eda71ac99b31379"
        }
      ],
      "title": "video: fbdev: cirrusfb: check pixclock to avoid divide by zero",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47641",
    "datePublished": "2025-02-26T01:54:12.680Z",
    "dateReserved": "2025-02-26T01:48:21.519Z",
    "dateUpdated": "2026-05-11T13:58:19.521Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-47641",
      "date": "2026-10-01",
      "epss": "0.00255",
      "percentile": "0.15473"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "drivers/video/fbdev/cirrusfb.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "c656d04247a2654ede5cead2ecbf83431dad5261",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "40b13e3d85744210db13457785646634e2d056bd",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "53a2088a396cfa1da92690a1da289634cd73bf0d",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "8c7e2141fb89c620ab4e41512e262fbf25b8260d",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "6fe23ff94e7840097202e85c148688940b37c9b1",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "45800c42ef000f417270bcfc08630e42486fca99",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "e498b504f8c81b07efab9febf8503448de4dc9cf",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "5c6f402bdcf9e7239c6bc7087eda71ac99b31379",
                    "status": "affected",
                    "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "drivers/video/fbdev/cirrusfb.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "2.6.12"
                  },
                  {
                    "lessThan": "2.6.12",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "4.9.*",
                    "status": "unaffected",
                    "version": "4.9.311",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "4.14.*",
                    "status": "unaffected",
                    "version": "4.14.276",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "4.19.*",
                    "status": "unaffected",
                    "version": "4.19.238",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.4.*",
                    "status": "unaffected",
                    "version": "5.4.189",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.10.*",
                    "status": "unaffected",
                    "version": "5.10.110",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.15.*",
                    "status": "unaffected",
                    "version": "5.15.33",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.16.*",
                    "status": "unaffected",
                    "version": "5.16.19",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.17.*",
                    "status": "unaffected",
                    "version": "5.17.2",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "5.18",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "C86EFD13-93D4-4385-83E8-C665BE8F570F",
                    "versionEndExcluding": "4.9.311",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "6D9B028C-6313-47F9-94B7-5F8122345E49",
                    "versionEndExcluding": "4.14.276",
                    "versionStartIncluding": "4.10",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "FA28527A-11D3-41D2-9C4C-ECAC0D6A4A2D",
                    "versionEndExcluding": "4.19.238",
                    "versionStartIncluding": "4.15",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "8CB6E8F5-C2B1-46F3-A807-0F6104AC340F",
                    "versionEndExcluding": "5.4.189",
                    "versionStartIncluding": "4.20",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "91D3BFD0-D3F3-4018-957C-96CCBF357D79",
                    "versionEndExcluding": "5.10.110",
                    "versionStartIncluding": "5.5",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "27C42AE8-B387-43E2-938A-E1C8B40BE6D5",
                    "versionEndExcluding": "5.15.33",
                    "versionStartIncluding": "5.11",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "20C43679-0439-405A-B97F-685BEE50613B",
                    "versionEndExcluding": "5.16.19",
                    "versionStartIncluding": "5.16",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "210C679C-CF84-44A3-8939-E629C87E54BF",
                    "versionEndExcluding": "5.17.2",
                    "versionStartIncluding": "5.17",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvideo: fbdev: cirrusfb: check pixclock to avoid divide by zero\n\nDo a sanity check on pixclock value to avoid divide by zero.\n\nIf the pixclock value is zero, the cirrusfb driver will round up\npixclock to get the derived frequency as close to maxclock as\npossible.\n\nSyzkaller reported a divide error in cirrusfb_check_pixclock.\n\ndivide error: 0000 [#1] SMP KASAN PTI\nCPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2\nRIP: 0010:cirrusfb_check_var+0x6f1/0x1260\n\nCall Trace:\n fb_set_var+0x398/0xf90\n do_fb_ioctl+0x4b8/0x6f0\n fb_ioctl+0xeb/0x130\n __x64_sys_ioctl+0x19d/0x220\n do_syscall_64+0x3a/0x80\n entry_SYSCALL_64_after_hwframe+0x44/0xae"
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: video: fbdev: cirrusfb: comprobar pixclock para evitar la divisi\u00f3n por cero Realice una comprobaci\u00f3n de la depuraci\u00f3n del valor de pixclock para evitar la divisi\u00f3n por cero. Si el valor de pixclock es cero, el controlador cirrusfb redondear\u00e1 el valor de pixclock para obtener la frecuencia derivada lo m\u00e1s cercana posible a maxclock. Syzkaller inform\u00f3 un error de divisi\u00f3n en cirrusfb_check_pixclock. Error de divisi\u00f3n: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 14938 Comm: cirrusfb_test No contaminado 5.15.0-rc6 #1 Nombre del hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS 1.11.0-2 RIP: 0010:cirrusfb_check_var+0x6f1/0x1260 Seguimiento de llamadas: fb_set_var+0x398/0xf90 do_fb_ioctl+0x4b8/0x6f0 fb_ioctl+0xeb/0x130 __x64_sys_ioctl+0x19d/0x220 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae"
          }
        ],
        "id": "CVE-2021-47641",
        "lastModified": "2026-06-17T04:18:13.427",
        "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"
            },
            {
              "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": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2021-47641",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-10-01T19:50:40.514584Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2025-02-26T06:37:05.883",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/40b13e3d85744210db13457785646634e2d056bd"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/45800c42ef000f417270bcfc08630e42486fca99"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/53a2088a396cfa1da92690a1da289634cd73bf0d"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/5c6f402bdcf9e7239c6bc7087eda71ac99b31379"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/6fe23ff94e7840097202e85c148688940b37c9b1"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/8c7e2141fb89c620ab4e41512e262fbf25b8260d"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/c656d04247a2654ede5cead2ecbf83431dad5261"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/e498b504f8c81b07efab9febf8503448de4dc9cf"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-369"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-369"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-29T22:44:51+00:00",
      "cve": "CVE-2021-47641",
      "id": "CVE-2021-47641",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: video: fbdev: cirrusfb: check pixclock to avoid divide by zero",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47641.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-13T23:55:12Z",
      "cve": "CVE-2021-47641",
      "id": "CVE-2021-47641",
      "initial_release_date": "2025-02-27T03:14:22Z",
      "product_status:known_affected": "467",
      "product_status:known_not_affected": "271",
      "product_status:recommended": "293",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-47641",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-47641.json",
      "version": "47"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "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"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2021-47641",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2025-10-01T19:50:40.514584Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "cweId": "CWE-369",
                    "description": "CWE-369 Divide By Zero",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2025-10-01T16:01:50.826Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "Linux",
              "programFiles": [
                "drivers/video/fbdev/cirrusfb.c"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
                  "lessThan": "c656d04247a2654ede5cead2ecbf83431dad5261",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "40b13e3d85744210db13457785646634e2d056bd",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "53a2088a396cfa1da92690a1da289634cd73bf0d",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "8c7e2141fb89c620ab4e41512e262fbf25b8260d",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "6fe23ff94e7840097202e85c148688940b37c9b1",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "45800c42ef000f417270bcfc08630e42486fca99",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "e498b504f8c81b07efab9febf8503448de4dc9cf",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                },
                {
                  "lessThan": "5c6f402bdcf9e7239c6bc7087eda71ac99b31379",
                  "status": "affected",
                  "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                  "versionType": "git"
                }
              ]
            },
            {
              "defaultStatus": "affected",
              "product": "Linux",
              "programFiles": [
                "drivers/video/fbdev/cirrusfb.c"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
                  "lessThanOrEqual": "4.9.*",
                  "status": "unaffected",
                  "version": "4.9.311",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "4.14.*",
                  "status": "unaffected",
                  "version": "4.14.276",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "4.19.*",
                  "status": "unaffected",
                  "version": "4.19.238",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.4.*",
                  "status": "unaffected",
                  "version": "5.4.189",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.10.*",
                  "status": "unaffected",
                  "version": "5.10.110",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.15.*",
                  "status": "unaffected",
                  "version": "5.15.33",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.16.*",
                  "status": "unaffected",
                  "version": "5.16.19",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.17.*",
                  "status": "unaffected",
                  "version": "5.17.2",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "*",
                  "status": "unaffected",
                  "version": "5.18",
                  "versionType": "original_commit_for_fix"
                }
              ]
            }
          ],
          "cpeApplicability": [
            {
              "nodes": [
                {
                  "cpeMatch": [
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "4.9.311",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "4.14.276",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "4.19.238",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.4.189",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.10.110",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.15.33",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.16.19",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.17.2",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.18",
                      "vulnerable": true
                    }
                  ],
                  "negate": false,
                  "operator": "OR"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvideo: fbdev: cirrusfb: check pixclock to avoid divide by zero\n\nDo a sanity check on pixclock value to avoid divide by zero.\n\nIf the pixclock value is zero, the cirrusfb driver will round up\npixclock to get the derived frequency as close to maxclock as\npossible.\n\nSyzkaller reported a divide error in cirrusfb_check_pixclock.\n\ndivide error: 0000 [#1] SMP KASAN PTI\nCPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2\nRIP: 0010:cirrusfb_check_var+0x6f1/0x1260\n\nCall Trace:\n fb_set_var+0x398/0xf90\n do_fb_ioctl+0x4b8/0x6f0\n fb_ioctl+0xeb/0x130\n __x64_sys_ioctl+0x19d/0x220\n do_syscall_64+0x3a/0x80\n entry_SYSCALL_64_after_hwframe+0x44/0xae"
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2025-12-10T07:12:55.389Z",
            "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "shortName": "Linux"
          },
          "references": [
            {
              "url": "https://git.kernel.org/stable/c/c656d04247a2654ede5cead2ecbf83431dad5261"
            },
            {
              "url": "https://git.kernel.org/stable/c/1d3fb46439ad4e8f0c5739eb33d1875ac9e0f135"
            },
            {
              "url": "https://git.kernel.org/stable/c/40b13e3d85744210db13457785646634e2d056bd"
            },
            {
              "url": "https://git.kernel.org/stable/c/53a2088a396cfa1da92690a1da289634cd73bf0d"
            },
            {
              "url": "https://git.kernel.org/stable/c/8c7e2141fb89c620ab4e41512e262fbf25b8260d"
            },
            {
              "url": "https://git.kernel.org/stable/c/6fe23ff94e7840097202e85c148688940b37c9b1"
            },
            {
              "url": "https://git.kernel.org/stable/c/45800c42ef000f417270bcfc08630e42486fca99"
            },
            {
              "url": "https://git.kernel.org/stable/c/e498b504f8c81b07efab9febf8503448de4dc9cf"
            },
            {
              "url": "https://git.kernel.org/stable/c/5c6f402bdcf9e7239c6bc7087eda71ac99b31379"
            }
          ],
          "title": "video: fbdev: cirrusfb: check pixclock to avoid divide by zero",
          "x_generator": {
            "engine": "bippy-1.2.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "assignerShortName": "Linux",
        "cveId": "CVE-2021-47641",
        "datePublished": "2025-02-26T01:54:12.680Z",
        "dateReserved": "2025-02-26T01:48:21.519Z",
        "dateUpdated": "2025-12-10T07:12:55.389Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.