{"id":"CVE-2026-99024","title":"optee: register TEE devices only once fully initialized","summary":"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 stru…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 262062c01f5a817104c88bf6eacb7c6ffdc7018d","Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 8cae1605be8a047ae3a62df07b9474d61462c4f6","Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 681adbc9c7a820279582a295e183fa6a1d1b4ec4","Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 2f7240f0a6fd83df274fc0a2abf0609b4e6bd388","Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < c108feca0a096f8db25d1b69130035025e9e936d","Linux 4.12"],"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T12:21:08.551Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99024","references":[{"url":"https://git.kernel.org/stable/c/262062c01f5a817104c88bf6eacb7c6ffdc7018d"},{"url":"https://git.kernel.org/stable/c/8cae1605be8a047ae3a62df07b9474d61462c4f6"},{"url":"https://git.kernel.org/stable/c/681adbc9c7a820279582a295e183fa6a1d1b4ec4"},{"url":"https://git.kernel.org/stable/c/2f7240f0a6fd83df274fc0a2abf0609b4e6bd388"},{"url":"https://git.kernel.org/stable/c/c108feca0a096f8db25d1b69130035025e9e936d"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.535Z","slug":"CVE-2026-99024","body":"## Overview\n\nIn 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->desc 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->call_queue.mutex is not initialized by optee_cq_init()\n  - optee->supp mutex and completions is not initialized by\n    optee_supp_init()\n  - optee->rpmb_dev_mutex is not initialized yet,\n  - the message argument cache is not initialized by\n    optee_shm_arg_cache_init()\n  - optee->ctx 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]\n\n## Affected\n\n- `Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 262062c01f5a817104c88bf6eacb7c6ffdc7018d`\n- `Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 8cae1605be8a047ae3a62df07b9474d61462c4f6`\n- `Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 681adbc9c7a820279582a295e183fa6a1d1b4ec4`\n- `Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < 2f7240f0a6fd83df274fc0a2abf0609b4e6bd388`\n- `Linux >= 4fb0a5eb364d239722e745c02aef0dbd4e0f1ad2 < c108feca0a096f8db25d1b69130035025e9e936d`\n- `Linux 4.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}