{"id":"AZL-104379","summary":"CVE-2026-97564 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject userspace cifs.idmap descriptions\n\ncifs.idmap key descriptions carry authority-bearing fields (owner and\ngroup SIDs and uid/gid values in \"os:\"/\"gs:\"/\"oi:\"/\"gi:\" form) that the\ncifs.idmap upcall helper treats as kernel-originating inputs.  Unlike\nits sibling cifs.spnego, the cifs.idmap key type has no vet_description\nhook, so userspace can create keys of this type through\nrequest_key(2)/add_key(2) and supply those fields without CIFS origin.\nA request_key(2) call with a non-NULL callout then drives a root\nusermodehelper upcall (/sbin/request-key -\u003e cifs.idmap) that consumes\nthe unvetted description in root context.\n\nOnly accept cifs.idmap descriptions while CIFS is using its private\nroot_cred to request the key.  id_to_sid()/sid_to_id() already run\nunder override_creds(root_cred), so the kernel-originated path is\nunaffected.\n\nThis mirrors commit 3da1fdf4efbc (\"smb: client: reject userspace\ncifs.spnego descriptions\"), which applied the same restriction to\ncifs.spnego.","modified":"2026-09-26T14:16:20.065385319Z","published":"2026-09-25T11:17:07Z","upstream":["CVE-2026-97564"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97564"}],"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-104379.json"}}],"schema_version":"1.9.0"}