{"id":"AZL-104549","summary":"CVE-2026-98033 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve inner map identity in callback frames\n\nCallback frame constructors initialize map-typed argument registers with\n__mark_reg_known_zero() and then restore map_ptr. This clears map_uid,\nwhich is the only field distinguishing inner maps that share an\ninner_map_meta template.\n\nWhen a timer callback invokes bpf_for_each_map_elem() on a second inner\nmap, both the saved first map and the second map value can reach the nested\ncallback as the same template with map_uid zero. bpf_timer_init() then\naccepts pairing the timer from the second map with the first map.\n\nThe runtime records the first map in the timer without taking a reference.\nFreeing that map does not find the timer stored in the second map, so a\nlater timer callback dereferences the freed map.\n\nCopy map_uid from the same caller register as map_ptr when constructing\nfor-each, timer/workqueue, and task-work callback arguments. The existing\nidentity check can then reject mismatched inner maps while allowing a\ncallback value to be paired with its actual map.","modified":"2026-09-27T05:34:32Z","published":"2026-09-25T11:17:32Z","upstream":["CVE-2026-98033"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98033"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-104549.json"}}],"schema_version":"1.9.0"}