Vulnerability-Lookup

FKIE_CVE-2021-47338

Vulnerability from fkie_nvd - Published: 2024-05-21 15:15 - Updated: 2026-08-04 10:16

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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: fbmem: Do not delete the mode that is still in use The execution of fb_delete_videomode() is not based on the result of the previous fbcon_mode_deleted(). As a result, the mode is directly deleted, regardless of whether it is still in use, which may cause UAF. ================================================================== BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \ drivers/video/fbdev/core/modedb.c:924 Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962 CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ... Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:118 print_address_description+0x6c/0x640 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report+0x13d/0x1e0 mm/kasan/report.c:562 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 18960: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1541 [inline] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574 slab_free mm/slub.c:3139 [inline] kfree+0xca/0x3d0 mm/slub.c:4121 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126	Patch
af854a3a-2127-422b-91ae-364da2661108	https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	5.14

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbmem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "359311b85ebec7c07c3a08ae2f3def946cad33fa",
              "status": "affected",
              "version": "13ff178ccd6d3b8074c542a911300b79c4eec255",
              "versionType": "git"
            },
            {
              "lessThan": "087bff9acd2ec6db3f61aceb3224bde90fe0f7f8",
              "status": "affected",
              "version": "13ff178ccd6d3b8074c542a911300b79c4eec255",
              "versionType": "git"
            },
            {
              "lessThan": "f193509afc7ff37a46862610c93b896044d5b693",
              "status": "affected",
              "version": "13ff178ccd6d3b8074c542a911300b79c4eec255",
              "versionType": "git"
            },
            {
              "lessThan": "d6e76469157d8f240e5dec6f8411aa8d306b1126",
              "status": "affected",
              "version": "13ff178ccd6d3b8074c542a911300b79c4eec255",
              "versionType": "git"
            },
            {
              "lessThan": "0af778269a522c988ef0b4188556aba97fb420cc",
              "status": "affected",
              "version": "13ff178ccd6d3b8074c542a911300b79c4eec255",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbmem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.134",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.13.*",
              "status": "unaffected",
              "version": "5.13.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B6466E90-E229-4926-BEA7-9D888047B9C9",
              "versionEndExcluding": "5.4.134",
              "versionStartIncluding": "5.3",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7C1E6FB6-53C8-4DC4-8AE5-93094BA39F62",
              "versionEndExcluding": "5.10.52",
              "versionStartIncluding": "5.5",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "34C1A2F4-DD44-4CF1-8FD4-751A0D746A9E",
              "versionEndExcluding": "5.12.19",
              "versionStartIncluding": "5.11",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F93FA3CC-0C79-410B-A7D7-245C2AA0723A",
              "versionEndExcluding": "5.13.4",
              "versionStartIncluding": "5.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.14:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "71268287-21A8-4488-AA4F-23C473153131",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbmem: Do not delete the mode that is still in use\n\nThe execution of fb_delete_videomode() is not based on the result of the\nprevious fbcon_mode_deleted(). As a result, the mode is directly deleted,\nregardless of whether it is still in use, which may cause UAF.\n\n==================================================================\nBUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \\\ndrivers/video/fbdev/core/modedb.c:924\nRead of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962\n\nCPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...\nCall Trace:\n __dump_stack lib/dump_stack.c:77 [inline]\n dump_stack+0x137/0x1be lib/dump_stack.c:118\n print_address_description+0x6c/0x640 mm/kasan/report.c:385\n __kasan_report mm/kasan/report.c:545 [inline]\n kasan_report+0x13d/0x1e0 mm/kasan/report.c:562\n fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924\n fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746\n fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nFreed by task 18960:\n kasan_save_stack mm/kasan/common.c:48 [inline]\n kasan_set_track+0x3d/0x70 mm/kasan/common.c:56\n kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355\n __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422\n slab_free_hook mm/slub.c:1541 [inline]\n slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574\n slab_free mm/slub.c:3139 [inline]\n kfree+0xca/0x3d0 mm/slub.c:4121\n fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104\n fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: fbmem: No elimina el modo que a\u00fan est\u00e1 en uso. La ejecuci\u00f3n de fb_delete_videomode() no se basa en el resultado del fbcon_mode_deleted() anterior. Como resultado, el modo se elimina directamente, independientemente de si todav\u00eda est\u00e1 en uso, lo que puede causar UAF. ==================================================== ================ BUG: KASAN: use-after-free en fb_mode_is_equal+0x36e/0x5e0 \\ drivers/video/fbdev/core/modedb.c:924 Lectura de tama\u00f1o 4 en addr ffff88807e0ddb1c por tarea syz-executor.0/18962 CPU: 2 PID: 18962 Comm: syz-executor.0 No contaminado 5.10.45-rc1+ #3 Nombre de hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS .. Seguimiento de llamadas: __dump_stack lib/dump_stack.c:77 [en l\u00ednea] dump_stack+0x137/0x1be lib/dump_stack.c:118 print_address_description+0x6c/0x640 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c: 545 [en l\u00ednea] kasan_report+0x13d/0x1e0 mm/kasan/report.c:562 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon .c:2746 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [en l\u00ednea ] __do_sys_ioctl fs/ioctl.c:753 [en l\u00ednea] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 Entry_SYSCALL_64_after_hwframe+0x44/0xa9 Liberado por tarea 18960: kasan_save_stack mm/kasan/common.c:48 [en l\u00ednea] kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x108/0x140 mm/kasan/ common.c:422 slab_free_hook mm/slub.c:1541 [en l\u00ednea] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574 slab_free mm/slub.c:3139 [en l\u00ednea] kfree+0xca/0x3d0 mm/slub.c: 4121 fb_delete_videomode+0x56a/0x820 controladores/video/fbdev/core/modedb.c:1104 fb_set_var+0x1f3/0xdb0 controladores/video/fbdev/core/fbmem.c:978 do_fb_ioctl+0x4d9/0x6e0 controladores/video/fbdev/core/ fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [en l\u00ednea] __do_sys_ioctl fs/ioctl.c:753 [en l\u00ednea] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/ common.c:46 entrada_SYSCALL_64_after_hwframe+0x44/0xa9"
    }
  ],
  "id": "CVE-2021-47338",
  "lastModified": "2026-08-04T10:16:58.303",
  "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"
      },
      {
        "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": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2021-47338",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2024-06-12T15:00:51.209603Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2024-05-21T15:15:20.610",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2021-47338 (GCVE-0-2021-47338)

Vulnerability from cvelistv5 – Published: 2024-05-21 14:35 – Updated: 2026-08-05 08:47

Title

fbmem: Do not delete the mode that is still in use

Summary

Severity

7.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-06-12 15:00 UTC

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/359311b85ebec7c07…
https://git.kernel.org/stable/c/087bff9acd2ec6db3…
https://git.kernel.org/stable/c/f193509afc7ff37a4…
https://git.kernel.org/stable/c/d6e76469157d8f240…
https://git.kernel.org/stable/c/0af778269a522c988…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 13ff178ccd6d3b8074c542a911300b79c4eec255 , < 359311b85ebec7c07c3a08ae2f3def946cad33fa (git) Affected: 13ff178ccd6d3b8074c542a911300b79c4eec255 , < 087bff9acd2ec6db3f61aceb3224bde90fe0f7f8 (git) Affected: 13ff178ccd6d3b8074c542a911300b79c4eec255 , < f193509afc7ff37a46862610c93b896044d5b693 (git) Affected: 13ff178ccd6d3b8074c542a911300b79c4eec255 , < d6e76469157d8f240e5dec6f8411aa8d306b1126 (git) Affected: 13ff178ccd6d3b8074c542a911300b79c4eec255 , < 0af778269a522c988ef0b4188556aba97fb420cc (git)
Linux	Linux	Affected: 5.3 Unaffected: 0 , < 5.3 (semver) Unaffected: 5.4.134 , ≤ 5.4.* (semver) Unaffected: 5.10.52 , ≤ 5.10.* (semver) Unaffected: 5.12.19 , ≤ 5.12.* (semver) Unaffected: 5.13.4 , ≤ 5.13.* (semver) Unaffected: 5.14 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47338",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-06-12T15:00:51.209603Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
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        "providerMetadata": {
          "dateUpdated": "2024-06-12T15:01:02.502Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:32:08.605Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
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            "url": "https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8"
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            "url": "https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc"
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        "title": "CVE Program Container"
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    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/video/fbdev/core/fbmem.c"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.134",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.12.*",
              "status": "unaffected",
              "version": "5.12.19",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "5.13.*",
              "status": "unaffected",
              "version": "5.13.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.14",
              "versionType": "original_commit_for_fix"
            }
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      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.134",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.52",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "5.12.19",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.13.4",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.14",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbmem: Do not delete the mode that is still in use\n\nThe execution of fb_delete_videomode() is not based on the result of the\nprevious fbcon_mode_deleted(). As a result, the mode is directly deleted,\nregardless of whether it is still in use, which may cause UAF.\n\n==================================================================\nBUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \\\ndrivers/video/fbdev/core/modedb.c:924\nRead of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962\n\nCPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...\nCall Trace:\n __dump_stack lib/dump_stack.c:77 [inline]\n dump_stack+0x137/0x1be lib/dump_stack.c:118\n print_address_description+0x6c/0x640 mm/kasan/report.c:385\n __kasan_report mm/kasan/report.c:545 [inline]\n kasan_report+0x13d/0x1e0 mm/kasan/report.c:562\n fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924\n fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746\n fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nFreed by task 18960:\n kasan_save_stack mm/kasan/common.c:48 [inline]\n kasan_set_track+0x3d/0x70 mm/kasan/common.c:56\n kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355\n __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422\n slab_free_hook mm/slub.c:1541 [inline]\n slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574\n slab_free mm/slub.c:3139 [inline]\n kfree+0xca/0x3d0 mm/slub.c:4121\n fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104\n fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978\n do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108\n vfs_ioctl fs/ioctl.c:48 [inline]\n __do_sys_ioctl fs/ioctl.c:753 [inline]\n __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739\n do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46\n entry_SYSCALL_64_after_hwframe+0x44/0xa9"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Triggered via local ioctl(FBIOPUT_VSCREENINFO) on /dev/fbN through do_fb_ioctl \u2192 fb_set_var; there is no network or adjacent-protocol path into fbmem/fbcon.\nAC:L - The attacker fully controls mode setup and FB_ACTIVATE_INV_MODE deletion; ignoring fbcon_mode_deleted()\u0027s in-use result deterministically frees a modelist entry while fb_display[].mode still points at it, with no attacker-independent race or layout requirement.\nPR:L - do_fb_ioctl/FBIOPUT_VSCREENINFO performs no capability check; access is only DAC on /dev/fbN, which seated users, video-group members, and embedded/Android graphics processes commonly have without init-namespace root.\nUI:N - The attacker opens the framebuffer device and issues the ioctl sequence directly; no separate victim action is required.\nS:U - Impact is kernel heap use-after-free and potential privilege escalation within the same host security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a use-after-free of a groomable kmalloc fb_modelist object whose dangling mode pointer is later read (e.g. fb_mode_is_equal/display_to_var), enabling heap disclosure per UAF scoring guidance.\nI:H - UAF of a sprayable slab object allows reclaim/type confusion and corruption of kernel state through subsequent fbcon/fb_set_var paths, enabling write primitives and control-flow hijack.\nA:H - The syzkaller/KASAN report is a slab use-after-free that oopses in fb_mode_is_equal(); dereferencing the dangling pointer after reclaim or page return can panic the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:47:17.872Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa"
        },
        {
          "url": "https://git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8"
        },
        {
          "url": "https://git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693"
        },
        {
          "url": "https://git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126"
        },
        {
          "url": "https://git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc"
        }
      ],
      "title": "fbmem: Do not delete the mode that is still in use",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47338",
    "datePublished": "2024-05-21T14:35:47.028Z",
    "dateReserved": "2024-05-21T14:28:16.978Z",
    "dateUpdated": "2026-08-05T08:47:17.872Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.