In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats() When blkg_alloc() is called to allocate a blkcg_gq structure with the associated blkg_iostat_set's, there are 2 fields within blkg_iostat_set that requires proper initialization - blkg & sync. The former field was introduced by commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") while the later one was introduced by commit f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat"). Unfortunately those fields in the blkg_iostat_set's are not properly re-initialized when they are cleared in v1's blkcg_reset_stats(). This can lead to a kernel panic due to NULL pointer access of the blkg pointer. The missing initialization of sync is less problematic and can be a problem in a debug kernel due to missing lockdep initialization. Fix these problems by re-initializing them after memory clearing.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979 cve-icon cve-icon
https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2 cve-icon cve-icon
https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025091855-CVE-2023-53421-0dd9@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2023-53421 cve-icon
https://www.cve.org/CVERecord?id=CVE-2023-53421 cve-icon
History

Fri, 19 Sep 2025 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Fri, 19 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Thu, 18 Sep 2025 16:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats() When blkg_alloc() is called to allocate a blkcg_gq structure with the associated blkg_iostat_set's, there are 2 fields within blkg_iostat_set that requires proper initialization - blkg & sync. The former field was introduced by commit 3b8cc6298724 ("blk-cgroup: Optimize blkcg_rstat_flush()") while the later one was introduced by commit f73316482977 ("blk-cgroup: reimplement basic IO stats using cgroup rstat"). Unfortunately those fields in the blkg_iostat_set's are not properly re-initialized when they are cleared in v1's blkcg_reset_stats(). This can lead to a kernel panic due to NULL pointer access of the blkg pointer. The missing initialization of sync is less problematic and can be a problem in a debug kernel due to missing lockdep initialization. Fix these problems by re-initializing them after memory clearing.
Title blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-09-18T16:04:04.526Z

Updated: 2025-09-18T16:04:04.526Z

Reserved: 2025-09-17T14:54:09.741Z

Link: CVE-2023-53421

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-18T16:15:45.897

Modified: 2025-09-18T16:15:45.897

Link: CVE-2023-53421

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-09-18T00:00:00Z

Links: CVE-2023-53421 - Bugzilla