CVE-2026-99024

high

Description

In the Linux kernel, the following vulnerability has been resolved: optee: register TEE devices only once fully initialized optee_probe() called tee_device_register() on both the client and the supplicant device before the rest of struct optee had been initialized. tee_device_register() calls cdev_device_add(), which does two things at once: it creates /dev/tee0 and /dev/teepriv0, and it links the device into the tee class so that class_find_device() can find it. From that moment on the device is reachable both from user space via tee_open() and from kernel space via tee_client_open_context(). The only gate in teedev_open() is tee_device_get(), which merely checks that teedev->desc is non-NULL, which was already set by tee_device_alloc(). Therefore, there is effectively no gate at all. A context opened in that window can run against a struct optee where - optee->call_queue.mutex is not initialized by optee_cq_init() - optee->supp mutex and completions is not initialized by optee_supp_init() - optee->rpmb_dev_mutex is not initialized yet, - the message argument cache is not initialized by optee_shm_arg_cache_init() - optee->ctx is still NULL Any open session or invoke during this window takes uninitialized mutexes and dereferences a NULL pointer. Fix it by moving both tee_device_register() calls down to the point where all of struct optee is set up. [JW: adding fixes and cc]

References

https://git.kernel.org/stable/c/db36c37a2c3f13d5fd0f1afd8e2391d6c50793e6

https://git.kernel.org/stable/c/c108feca0a096f8db25d1b69130035025e9e936d

https://git.kernel.org/stable/c/8de131e1a2ab379641bb475f1bcb472a1a1d75df

https://git.kernel.org/stable/c/8cae1605be8a047ae3a62df07b9474d61462c4f6

https://git.kernel.org/stable/c/6b21a716ccab7fa42e8dfa3118000bc5274004ab

https://git.kernel.org/stable/c/681adbc9c7a820279582a295e183fa6a1d1b4ec4

https://git.kernel.org/stable/c/2f7240f0a6fd83df274fc0a2abf0609b4e6bd388

https://git.kernel.org/stable/c/262062c01f5a817104c88bf6eacb7c6ffdc7018d

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-108818

Details

Source: Mitre, NVD

Published: 2026-10-23

Updated: 2026-10-30

Risk Information

CVSS v2

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.4

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00177