Vulnerability-Lookup

EUVD-2026-320249

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 07:39

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

JSON

To clipboard

{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T07:39:42.337402+00:00",
  "id": "EUVD-2026-320249"
}

CVE-2021-47634 (GCVE-0-2021-47634)

Vulnerability from cvelistv5 – Published: 2025-02-26 01:54 – Updated: 2026-05-23 15:20

Title

ubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl

Summary

In the Linux kernel, the following vulnerability has been resolved: ubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl Hulk Robot reported a KASAN report about use-after-free: ================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0x13d/0x160 Read of size 8 at addr ffff888035e37d98 by task ubiattach/1385 [...] Call Trace: klist_dec_and_del+0xa7/0x4a0 klist_put+0xc7/0x1a0 device_del+0x4d4/0xed0 cdev_device_del+0x1a/0x80 ubi_attach_mtd_dev+0x2951/0x34b0 [ubi] ctrl_cdev_ioctl+0x286/0x2f0 [ubi] Allocated by task 1414: device_add+0x60a/0x18b0 cdev_device_add+0x103/0x170 ubi_create_volume+0x1118/0x1a10 [ubi] ubi_cdev_ioctl+0xb7f/0x1ba0 [ubi] Freed by task 1385: cdev_device_del+0x1a/0x80 ubi_remove_volume+0x438/0x6c0 [ubi] ubi_cdev_ioctl+0xbf4/0x1ba0 [ubi] [...] ================================================================== The lock held by ctrl_cdev_ioctl is ubi_devices_mutex, but the lock held by ubi_cdev_ioctl is ubi->device_mutex. Therefore, the two locks can be concurrent. ctrl_cdev_ioctl contains two operations: ubi_attach and ubi_detach. ubi_detach is bug-free because it uses reference counting to prevent concurrency. However, uif_init and uif_close in ubi_attach may race with ubi_cdev_ioctl. uif_init will race with ubi_cdev_ioctl as in the following stack. cpu1 cpu2 cpu3 _______________________|________________________|______________________ ctrl_cdev_ioctl ubi_attach_mtd_dev uif_init ubi_cdev_ioctl ubi_create_volume cdev_device_add ubi_add_volume // sysfs exist kill_volumes ubi_cdev_ioctl ubi_remove_volume cdev_device_del // first free ubi_free_volume cdev_del // double free cdev_device_del And uif_close will race with ubi_cdev_ioctl as in the following stack. cpu1 cpu2 cpu3 _______________________|________________________|______________________ ctrl_cdev_ioctl ubi_attach_mtd_dev uif_init ubi_cdev_ioctl ubi_create_volume cdev_device_add ubi_debugfs_init_dev //error goto out_uif; uif_close kill_volumes ubi_cdev_ioctl ubi_remove_volume cdev_device_del // first free ubi_free_volume // double free The cause of this problem is that commit 714fb87e8bc0 make device "available" before it becomes accessible via sysfs. Therefore, we roll back the modification. We will fix the race condition between ubi device creation and udev by removing ubi_get_device in vol_attribute_show and dev_attribute_show.This avoids accessing uninitialized ubi_devices[ubi_num]. ubi_get_device is used to prevent devices from being deleted during sysfs execution. However, now kernfs ensures that devices will not be deleted before all reference counting are released. The key process is shown in the following stack. device_del device_remove_attrs device_remove_groups sysfs_remove_groups sysfs_remove_group remove_files kernfs_remove_by_name kernfs_remove_by_name_ns __kernfs_remove kernfs_drain

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: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-02-27 18:17 UTC

CWE

CWE-416 - Use After Free

Assigner

Linux mitre root Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/f149b1bd213820363…
https://git.kernel.org/stable/c/a8ecee49259f8f78d…
https://git.kernel.org/stable/c/d727fd32cbd1abf34…
https://git.kernel.org/stable/c/432b057f8e847ae5a…
https://git.kernel.org/stable/c/1a3f1cf8705483324…
https://git.kernel.org/stable/c/c32fe764191b8ae8b…
https://git.kernel.org/stable/c/5f9e9c223e48c2642…
https://git.kernel.org/stable/c/3cbf0e392f173ba0c…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < f149b1bd213820363731aa119e5011ca892a2aac (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < a8ecee49259f8f78d91ddb329ab2be7e6fd01974 (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < d727fd32cbd1abf3465f607021bc9c746f17b5a8 (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < 432b057f8e847ae5a2306515606f8d2defaca178 (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < 1a3f1cf87054833242fcd0218de0481cf855f888 (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < c32fe764191b8ae8b128588beb96e3718d9179d8 (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < 5f9e9c223e48c264241d2f34d0bfc29e5fcb5c1b (git) Affected: 714fb87e8bc05ff78255afc0dca981e8c5242785 , < 3cbf0e392f173ba0ce425968c8374a6aa3e90f2e (git) Affected: 016820bde3f0895d09fcad370415085ba0d1bd4a (git) Affected: 12f567db822241090b90c5645ea9146f6cf8fa42 (git) Affected: 31b0fca8ab9b9786fe6e5027c4a8587b47db5abf (git) Affected: 6117840dec60344167038f9511c3770d4c096eaa (git) Affected: bd7d3de27e7e1acce2e276074a498a82e0834663 (git) Affected: cdf25333b42fb889f086ef65d0734d0dbdc49f4e (git) Affected: ae32d1b98ba29408df87c0ed47877ca0f248eae7 (git) Affected: 4056337b1e81a1b137aa562133dc5430cd2fd19e (git) Affected: f3db4c640b32485105554e0bfd16bbde585f6fb0 (git) Affected: 3.2.84 , < 3.3 (semver) Affected: 3.10.103 , < 3.11 (semver) Affected: 3.12.63 , < 3.13 (semver) Affected: 3.14.77 , < 3.15 (semver) Affected: 3.16.39 , < 3.17 (semver) Affected: 3.18.40 , < 3.19 (semver) Affected: 4.1.31 , < 4.2 (semver) Affected: 4.4.19 , < 4.5 (semver) Affected: 4.7.2 , < 4.8 (semver)
Linux	Linux	Affected: 4.8 Unaffected: 0 , < 4.8 (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)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "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"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-47634",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-27T18:17:56.634866Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-416",
                "description": "CWE-416 Use After Free",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-02-27T18:22:36.034Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/mtd/ubi/build.c",
            "drivers/mtd/ubi/vmt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f149b1bd213820363731aa119e5011ca892a2aac",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "a8ecee49259f8f78d91ddb329ab2be7e6fd01974",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "d727fd32cbd1abf3465f607021bc9c746f17b5a8",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "432b057f8e847ae5a2306515606f8d2defaca178",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "1a3f1cf87054833242fcd0218de0481cf855f888",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "c32fe764191b8ae8b128588beb96e3718d9179d8",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "5f9e9c223e48c264241d2f34d0bfc29e5fcb5c1b",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "lessThan": "3cbf0e392f173ba0ce425968c8374a6aa3e90f2e",
              "status": "affected",
              "version": "714fb87e8bc05ff78255afc0dca981e8c5242785",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "016820bde3f0895d09fcad370415085ba0d1bd4a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "12f567db822241090b90c5645ea9146f6cf8fa42",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "31b0fca8ab9b9786fe6e5027c4a8587b47db5abf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6117840dec60344167038f9511c3770d4c096eaa",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bd7d3de27e7e1acce2e276074a498a82e0834663",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cdf25333b42fb889f086ef65d0734d0dbdc49f4e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ae32d1b98ba29408df87c0ed47877ca0f248eae7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4056337b1e81a1b137aa562133dc5430cd2fd19e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f3db4c640b32485105554e0bfd16bbde585f6fb0",
              "versionType": "git"
            },
            {
              "lessThan": "3.3",
              "status": "affected",
              "version": "3.2.84",
              "versionType": "semver"
            },
            {
              "lessThan": "3.11",
              "status": "affected",
              "version": "3.10.103",
              "versionType": "semver"
            },
            {
              "lessThan": "3.13",
              "status": "affected",
              "version": "3.12.63",
              "versionType": "semver"
            },
            {
              "lessThan": "3.15",
              "status": "affected",
              "version": "3.14.77",
              "versionType": "semver"
            },
            {
              "lessThan": "3.17",
              "status": "affected",
              "version": "3.16.39",
              "versionType": "semver"
            },
            {
              "lessThan": "3.19",
              "status": "affected",
              "version": "3.18.40",
              "versionType": "semver"
            },
            {
              "lessThan": "4.2",
              "status": "affected",
              "version": "4.1.31",
              "versionType": "semver"
            },
            {
              "lessThan": "4.5",
              "status": "affected",
              "version": "4.4.19",
              "versionType": "semver"
            },
            {
              "lessThan": "4.8",
              "status": "affected",
              "version": "4.7.2",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/mtd/ubi/build.c",
            "drivers/mtd/ubi/vmt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.8"
            },
            {
              "lessThan": "4.8",
              "status": "unaffected",
              "version": "0",
              "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": "4.14.276",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.19.238",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.189",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.110",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.33",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.16.19",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.17.2",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.18",
                  "versionStartIncluding": "4.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.2.84",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.10.103",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.12.63",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.14.77",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.16.39",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.18.40",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.1.31",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.4.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.7.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl\n\nHulk Robot reported a KASAN report about use-after-free:\n ==================================================================\n BUG: KASAN: use-after-free in __list_del_entry_valid+0x13d/0x160\n Read of size 8 at addr ffff888035e37d98 by task ubiattach/1385\n [...]\n Call Trace:\n  klist_dec_and_del+0xa7/0x4a0\n  klist_put+0xc7/0x1a0\n  device_del+0x4d4/0xed0\n  cdev_device_del+0x1a/0x80\n  ubi_attach_mtd_dev+0x2951/0x34b0 [ubi]\n  ctrl_cdev_ioctl+0x286/0x2f0 [ubi]\n\n Allocated by task 1414:\n  device_add+0x60a/0x18b0\n  cdev_device_add+0x103/0x170\n  ubi_create_volume+0x1118/0x1a10 [ubi]\n  ubi_cdev_ioctl+0xb7f/0x1ba0 [ubi]\n\n Freed by task 1385:\n  cdev_device_del+0x1a/0x80\n  ubi_remove_volume+0x438/0x6c0 [ubi]\n  ubi_cdev_ioctl+0xbf4/0x1ba0 [ubi]\n [...]\n ==================================================================\n\nThe lock held by ctrl_cdev_ioctl is ubi_devices_mutex, but the lock held\nby ubi_cdev_ioctl is ubi-\u003edevice_mutex. Therefore, the two locks can be\nconcurrent.\n\nctrl_cdev_ioctl contains two operations: ubi_attach and ubi_detach.\nubi_detach is bug-free because it uses reference counting to prevent\nconcurrency. However, uif_init and uif_close in ubi_attach may race with\nubi_cdev_ioctl.\n\nuif_init will race with ubi_cdev_ioctl as in the following stack.\n           cpu1                   cpu2                  cpu3\n_______________________|________________________|______________________\nctrl_cdev_ioctl\n ubi_attach_mtd_dev\n  uif_init\n                           ubi_cdev_ioctl\n                            ubi_create_volume\n                             cdev_device_add\n   ubi_add_volume\n   // sysfs exist\n   kill_volumes\n                                                    ubi_cdev_ioctl\n                                                     ubi_remove_volume\n                                                      cdev_device_del\n                                                       // first free\n    ubi_free_volume\n     cdev_del\n     // double free\n   cdev_device_del\n\nAnd uif_close will race with ubi_cdev_ioctl as in the following stack.\n           cpu1                   cpu2                  cpu3\n_______________________|________________________|______________________\nctrl_cdev_ioctl\n ubi_attach_mtd_dev\n  uif_init\n                           ubi_cdev_ioctl\n                            ubi_create_volume\n                             cdev_device_add\n  ubi_debugfs_init_dev\n  //error goto out_uif;\n  uif_close\n   kill_volumes\n                                                    ubi_cdev_ioctl\n                                                     ubi_remove_volume\n                                                      cdev_device_del\n                                                       // first free\n    ubi_free_volume\n    // double free\n\nThe cause of this problem is that commit 714fb87e8bc0 make device\n\"available\" before it becomes accessible via sysfs. Therefore, we\nroll back the modification. We will fix the race condition between\nubi device creation and udev by removing ubi_get_device in\nvol_attribute_show and dev_attribute_show.This avoids accessing\nuninitialized ubi_devices[ubi_num].\n\nubi_get_device is used to prevent devices from being deleted during\nsysfs execution. However, now kernfs ensures that devices will not\nbe deleted before all reference counting are released.\nThe key process is shown in the following stack.\n\ndevice_del\n  device_remove_attrs\n    device_remove_groups\n      sysfs_remove_groups\n        sysfs_remove_group\n          remove_files\n            kernfs_remove_by_name\n              kernfs_remove_by_name_ns\n                __kernfs_remove\n                  kernfs_drain"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-23T15:20:22.061Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f149b1bd213820363731aa119e5011ca892a2aac"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8ecee49259f8f78d91ddb329ab2be7e6fd01974"
        },
        {
          "url": "https://git.kernel.org/stable/c/d727fd32cbd1abf3465f607021bc9c746f17b5a8"
        },
        {
          "url": "https://git.kernel.org/stable/c/432b057f8e847ae5a2306515606f8d2defaca178"
        },
        {
          "url": "https://git.kernel.org/stable/c/1a3f1cf87054833242fcd0218de0481cf855f888"
        },
        {
          "url": "https://git.kernel.org/stable/c/c32fe764191b8ae8b128588beb96e3718d9179d8"
        },
        {
          "url": "https://git.kernel.org/stable/c/5f9e9c223e48c264241d2f34d0bfc29e5fcb5c1b"
        },
        {
          "url": "https://git.kernel.org/stable/c/3cbf0e392f173ba0ce425968c8374a6aa3e90f2e"
        }
      ],
      "title": "ubi: Fix race condition between ctrl_cdev_ioctl and ubi_cdev_ioctl",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47634",
    "datePublished": "2025-02-26T01:54:09.135Z",
    "dateReserved": "2025-02-26T01:48:21.518Z",
    "dateUpdated": "2026-05-23T15:20:22.061Z",
    "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.

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.

Action not permitted

EUVD-2026-320249

CVE-2021-47634 (GCVE-0-2021-47634)

Tags

Sightings

Nomenclature

Related by attack behaviour