CVE-2021-47646

Feb. 27, 2025, 6:15 p.m.

7.8
High

Description

In the Linux kernel, the following vulnerability has been resolved: Revert "Revert "block, bfq: honor already-setup queue merges"" A crash [1] happened to be triggered in conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq: honor already-setup queue merges""). Yet, the reverted commit was not the one introducing the bug. In fact, it actually triggered a UAF introduced by a different commit, and now fixed by commit d29bd41428cf ("block, bfq: reset last_bfqq_created on group change"). So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") out. This commit restores it. [1] https://bugzilla.kernel.org/show_bug.cgi?id=214503

Product(s) Impacted

Product Versions
Linux Kernel
  • []

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-416
Use After Free
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

References

https://git.kernel.org/stable/c/15729ff8143f8135b03988a100a19e66d7cb7ecd
https://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607
https://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613
https://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6
https://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c
https://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871
https://git.kernel.org/stable/c/f990f0985eda59d4f29fc83fcf300c92b1225d39

Tags

416baaa9-dc9f-4396-8d5f-8c081fb06d67
CWE-416
2025-02-26
CVE-2021-47646

CVSS Score

7.8 / 10

CVSS Data - 3.1

  • Attack Vector: LOCAL
  • Attack Complexity: LOW
  • Privileges Required: LOW
  • Scope: UNCHANGED
  • Confidentiality Impact: HIGH
  • Integrity Impact: HIGH
  • Availability Impact: HIGH

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

    View Vector String

Timeline

Published: Feb. 26, 2025, 6:37 a.m.
Last Modified: Feb. 27, 2025, 6:15 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

416baaa9-dc9f-4396-8d5f-8c081fb06d67

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.