It was discovered in the Linux kernel before 4.11-rc8 that root can gain direct access to an internal keyring, such as '.dnsresolver' in RHEL-7 or '.builtintrusted_keys' upstream, by joining it as its session keyring. This allows root to bypass module signature verification by adding a new public key of its own devising to the keyring.
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-9604.json"
[
{
"id": "CVE-2016-9604-d07ba798",
"signature_type": "Line",
"digest": {
"threshold": 0.9,
"line_hashes": [
"75055363949899100138290333206349106204",
"221043752975010810243864096305268447466",
"204756210092455693677483901386974861683",
"325706760221785726251949888936275766499",
"224603698819922926482920036248526324231",
"256705400229784368062914627435529446838",
"272523242905308524969691429376859859593",
"40452965431786232208770958211346521157",
"103870101505868207056501056411157457208",
"309064054320801162277480402482652870226"
]
},
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@ee8f844e3c5a73b999edf733df1c529d6503ec2f",
"target": {
"file": "security/keys/keyctl.c"
},
"deprecated": false
},
{
"id": "CVE-2016-9604-e6df941c",
"signature_type": "Function",
"digest": {
"function_hash": "9236331033072010540349968922833060807",
"length": 276.0
},
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git@ee8f844e3c5a73b999edf733df1c529d6503ec2f",
"target": {
"function": "keyctl_join_session_keyring",
"file": "security/keys/keyctl.c"
},
"deprecated": false
}
]