{"id":"AZL-104586","summary":"CVE-2026-97923 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in. When that fails the field is leaked.\n\ncommit 656fe2ba85e8 (\"tracing: Use hist trigger's var_ref array to destroy\nvar_refs\") made destroy_hist_field() return early for\nHIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's\nvar_refs[] array instead. create_var_ref() adds the field to that array\nonly after init_var_ref() has succeeded, so on this path the field is in\nneither place and nothing frees it. The call was correct when it was\nwritten, before var refs were taken out of destroy_hist_field().\n\ninit_var_ref() cannot free it either. The caller owns the field, so\ninit_var_ref() undoes only its own string allocations and leaves the\nfield alone. Freeing it there would leave create_var_ref() passing freed\nmemory to destroy_hist_field(), which reads its flags.\n\nCall __destroy_hist_field(), which frees the field without consulting\nthe flag.","modified":"2026-09-27T05:34:32Z","published":"2026-09-25T11:17:19Z","upstream":["CVE-2026-97923"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97923"}],"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-104586.json"}}],"schema_version":"1.9.0"}