CVE-2026-99024

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]

Package Linux Kernel
Published 2026-10-23
Last modified 2026-10-23
Patch available
Yes

Affected versions

Linux kernel versions 4.12 and later are affected. Fixed in 6.6.160, 6.12.113, 6.18.57, 7.2.11, 7.3 and their respective stable series.

Affected from
≥ 4.12
Fixed in
✓ 6.6.160 6.6.x ✓ 6.12.113 6.12.x ✓ 6.18.57 6.18.x ✓ 7.2.11 7.2.x ✓ 7.3

Frequently asked questions

  • What is CVE-2026-99024?

    CVE-2026-99024 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.12 onward and has been patched in 6.6.160, 6.12.113, 6.18.57 and others. CVE-2026-99024 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-99024?

    Yes. CVE-2026-99024 has been patched. Fixed versions include 6.6.160, 6.12.113, 6.18.57 and others. If you are running Linux kernel 4.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-99024 actively exploited?

    No. CVE-2026-99024 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.