{"id":"AZL-110876","summary":"CVE-2026-99024 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\noptee: register TEE devices only once fully initialized\n\noptee_probe() called tee_device_register() on both the client and the\nsupplicant device before the rest of struct optee had been initialized.\n\ntee_device_register() calls cdev_device_add(), which does two things at\nonce: it creates /dev/tee0 and /dev/teepriv0, and it links the device\ninto the tee class so that class_find_device() can find it. From that\nmoment on the device is reachable both from user space via tee_open()\nand from kernel space via tee_client_open_context(). The only gate in\nteedev_open() is tee_device_get(), which merely checks that\nteedev-\u003edesc is non-NULL, which was already set by tee_device_alloc().\nTherefore, there is effectively no gate at all.\n\nA context opened in that window can run against a struct optee where\n\n  - optee-\u003ecall_queue.mutex is not initialized by optee_cq_init()\n  - optee-\u003esupp mutex and completions is not initialized by\n    optee_supp_init()\n  - optee-\u003erpmb_dev_mutex is not initialized yet,\n  - the message argument cache is not initialized by\n    optee_shm_arg_cache_init()\n  - optee-\u003ectx is still NULL\n\nAny open session or invoke during this window takes uninitialized\nmutexes and dereferences a NULL pointer.\n\nFix it by moving both tee_device_register() calls down to the point\nwhere all of struct optee is set up.\n\n[JW: adding fixes and cc]","modified":"2026-10-25T05:30:37Z","published":"2026-10-23T13:17:25Z","upstream":["CVE-2026-99024"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99024"}],"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-110876.json"}}],"schema_version":"1.9.0"}