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.

Fixes: 4fb0a5eb364d ("tee: add OP-TEE driver")
Cc: stable@vger.kernel.org
Signed-off-by: Shao-Fu Chen <shf.chen@mediatek.com>
[JW: adding fixes and cc]
Signed-off-by: Jens Wiklander <jens.wiklander@oss.qualcomm.com>

0 files changed, 0 insertions, 0 deletions