What is CVE-2021-47254?

CVE-2021-47254 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416). CVE-2021-47254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-47254?

CVE-2021-47254 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2021-47254?

No patch is currently available for CVE-2021-47254. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-47254 actively exploited?

CVE-2021-47254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2021-47254

High

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in gfs2_glock_shrink_scan The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to remove the glock from the lru list in __gfs2_glock_put(). On the shrink scan path, the same flag is cleared under lru_lock but because of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the put side can be made without deleting the glock from the lru list. Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to ensure correct behavior on both sides - clear GLF_LRU after list_del under lru_lock.

Package Linux Kernel

Published 2024-05-21

Last modified 2026-03-17

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2021-47254 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

References

The following references provide additional information about CVE-2021-47254 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/0364742decb0f02bc183404868b82896f7992595
Patch
Kernel patch commit
https://git.kernel.org/stable/c/094bf5670e762afa243d2c41a5c4ab71c7447bf4
Patch
Kernel patch commit
https://git.kernel.org/stable/c/1ab19c5de4c537ec0d9b21020395a5b5a6c059b2
Patch

8 patch commits total View all on NVD

Details

CVE ID CVE-2021-47254

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2024-05-21

Modified 2026-03-17

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-47254?

CVE-2021-47254 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . CVE-2021-47254 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-47254?

CVE-2021-47254 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2021-47254?

No patch is currently available for CVE-2021-47254. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-47254 actively exploited?

No — CVE-2021-47254 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →