CVE-2023-53421

MEDIUM EPSS 4.6%
Published Sep 18, 20259mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Sep 18, 2025 9mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
4.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 2

VendorProductVersionRange
linuxlinux_kernel*≥5.5  –  <6.3.13
linuxlinux_kernel*≥6.4  –  <6.4.4

References 6

  • git.kernel.org https://git.kernel.org/stable/c/0561aa6033dd181594116d705c41fc16e97161a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/58c135513562698f222a58ba07dbdfcfb268aa0d
  • git.kernel.org https://git.kernel.org/stable/c/892faa76be894d324bf48b12a55c7af7be2bad83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0561aa6033dd181594116d705c41fc16e97161a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/892faa76be894d324bf48b12a55c7af7be2bad83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8
    Patch