{"id":"AZL-71915","summary":"CVE-2023-53421 affecting package kernel 5.15.200.1-1","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":"2026-04-01T05:22:06.399622Z","published":"2025-09-18T16:15:45Z","upstream":["CVE-2023-53421"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53421"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-71915.json"}}],"schema_version":"1.7.5"}