CVE-2026-99024 - In the Linux kernel, the following vulnerability has been resolved: optee: register TEE devices only once fully initial
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]
INFORMATIONAL
Severity & confidence
Source severityinformational
Platform severityinformational
Confidencehigh
Exploitationunknown
CVSS-
Affected
Vendorslinux
Reporting sources (1)
NIST NVD - National Vulnerability Database
Timeline & provenance
Published2026-10-23T13:17:25
Last updated2026-10-26T13:03:58
Ingested2026-10-25T18:30:24
FreshnessNEAR-REAL-TIME
Threat typevulnerability
Recommended action
No recommended action published with this item - review the original source.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a government or cert-grade source (CISA, NCSC, NVD, ENISA, MSRC).
Source type: standards ยท Original: NIST NVD - National Vulnerability Database