CVE-2023-53421

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979	Patch
https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2	Patch
https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

History

No history.

Information

Published : 2025-09-18 16:15

Updated : 2026-01-14 20:16

NVD link : CVE-2023-53421

Mitre link : CVE-2023-53421

CVE.ORG link : CVE-2023-53421

JSON object : View

Products Affected

linux

linux_kernel

CWE

CWE-476

NULL Pointer Dereference

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