{"id":"CVE-2023-53421","summary":"blk-cgroup: Reinit blkg_iostat_set after clearing in blkcg_reset_stats()","details":"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 & 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.","modified":"2026-04-02T09:44:10.546977Z","published":"2025-09-18T16:04:04.526Z","related":["SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53421.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0561aa6033dd181594116d705c41fc16e97161a2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3d2af77e31ade05ff7ccc3658c3635ec1bea0979"},{"type":"WEB","url":"https://git.kernel.org/stable/c/892faa76be894d324bf48b12a55c7af7be2bad83"},{"type":"WEB","url":"https://git.kernel.org/stable/c/abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b0d26283af612b9e0cc3188b0b88ad7fdea447e8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53421.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53421"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f73316482977ac401ac37245c9df48079d4e11f3"},{"fixed":"0561aa6033dd181594116d705c41fc16e97161a2"},{"fixed":"892faa76be894d324bf48b12a55c7af7be2bad83"},{"fixed":"b0d26283af612b9e0cc3188b0b88ad7fdea447e8"},{"fixed":"abbce7f82613ea5eeefd0fc3c1c8e449b9cef2a2"},{"fixed":"3d2af77e31ade05ff7ccc3658c3635ec1bea0979"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53421.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}