Linux kernel optee: TEE devices registered before initialization
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
In the Linux kernel's OP-TEE driver, optee_probe() registered the client and supplicant TEE devices before struct optee was fully initialized. Once tee_device_register() ran, /dev/tee0 and /dev/teepriv0 were reachable from user space through tee_open() and from kernel space through tee_client_open_context(), and the only check in teedev_open(), tee_device_get(), passed as soon as teedev->desc was set. A context opened in that window could take uninitialized call queue, supplicant, RPMB and argument cache mutexes, or dereference a NULL optee->ctx. Red Hat rates it Moderate.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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]
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.12 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 4.12 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3 Patch available CNA
Remediation
Upgrade to a fixed Linux kernel: 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11 or 7.3. The fix moves both tee_device_register() calls to after all of struct optee is set up.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-23 Threatist record created from CVE-2026-99024
- 2026-10-23 Alias added: GHSA-qp8f-jjvm-547w
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-30 Fix available: Linux/[email protected], Linux/[email protected], Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/8de131e1a2ab379641bb475f1bcb472a1a1d75df
- https://git.kernel.org/stable/c/db36c37a2c3f13d5fd0f1afd8e2391d6c50793e6
- https://git.kernel.org/stable/c/6b21a716ccab7fa42e8dfa3118000bc5274004ab
- https://git.kernel.org/stable/c/262062c01f5a817104c88bf6eacb7c6ffdc7018d
- https://git.kernel.org/stable/c/8cae1605be8a047ae3a62df07b9474d61462c4f6
- https://git.kernel.org/stable/c/681adbc9c7a820279582a295e183fa6a1d1b4ec4
- https://git.kernel.org/stable/c/2f7240f0a6fd83df274fc0a2abf0609b4e6bd388
- https://git.kernel.org/stable/c/c108feca0a096f8db25d1b69130035025e9e936d
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Sources
- CVE-2026-99024 · CVE Program
- CVE-2026-99024 · NVD
- FIRST EPSS
- GHSA-qp8f-jjvm-547w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99024 · Red Hat security data · CC BY 4.0
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