{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2023-53421 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2023-53421 is a medium-severity vulnerability in Linux kernel, published on 18 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2023-53421 and fix it if it is affected.\n\nWhat it is: CVE-2023-53421 is a medium-severity vulnerability in Linux kernel, published on 18 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2023-53421 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2023-53421/ (Markdown: https://insights.sbomify.com/CVE-2023-53421/index.md)","id":"CVE-2023-53421","markdown":"https://insights.sbomify.com/CVE-2023-53421/index.md","name":"CVE-2023-53421","record":{"aliases":["AZL-71915","BELL-CVE-2023-53421","DEBIAN-CVE-2023-53421","GHSA-63xc-pmjj-q4vj","ROOT-OS-DEBIAN-11-CVE-2023-53421","ROOT-OS-DEBIAN-12-CVE-2023-53421","ROOT-OS-UBUNTU-2204-CVE-2023-53421","UBUNTU-CVE-2023-53421"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A missing re-initialization in the Linux kernel block cgroup code can cause a NULL pointer dereference, leading to a kernel panic and denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()\n\nWhen blkg_alloc() is called to allocate a blkcg_gq structure\nwith the associated blkg_iostat_set's, there are 2 fields within\nblkg_iostat_set that requires proper initialization - blkg \u0026 sync.\nThe former field was introduced by commit 3b8cc6298724 (\"blk-cgroup:\nOptimize blkcg_rstat_flush()\") while the later one was introduced by\ncommit f73316482977 (\"blk-cgroup: reimplement basic IO stats using\ncgroup rstat\").\n\nUnfortunately those fields in the blkg_iostat_set's are not properly\nre-initialized when they are cleared in v1's blkcg_reset_stats(). This\ncan lead to a kernel panic due to NULL pointer access of the blkg\npointer. The missing initialization of sync is less problematic and\ncan be a problem in a debug kernel due to missing lockdep initialization.\n\nFix these problems by re-initializing them after memory clearing.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()","id":"CVE-2023-53421","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2023"},"n_packages":0,"n_references":6,"next":{"headline":"wifi: iwlwifi: fw: fix memory leak in debugfs","id":"CVE-2023-53422"},"packages":[],"prev":{"headline":"ntfs: Fix panic about slab-out-of-bounds caused by ntfs_listxattr()","id":"CVE-2023-53420"},"products":["Linux"],"published":"2025-09-18","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-06-01","vendors":["Linux"]},"summary":"A missing re-initialization in the Linux kernel block cgroup code can cause a NULL pointer dereference, leading to a kernel panic and denial of service.","url":"https://insights.sbomify.com/CVE-2023-53421/"}