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.

Signed-off-by: Shao-Fu Chen shf.chen@mediatek.com --- drivers/tee/optee/ffa_abi.c | 16 ++++++++-------- drivers/tee/optee/smc_abi.c | 17 ++++++++--------- 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index 633715b98625..d3cc7c5fc1e9 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -1123,14 +1123,6 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)

optee_set_dev_group(optee);

- rc = tee_device_register(optee->teedev); - if (rc) - goto err_unreg_supp_teedev; - - rc = tee_device_register(optee->supp_teedev); - if (rc) - goto err_unreg_supp_teedev; - rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params); if (rc) goto err_unreg_supp_teedev; @@ -1159,6 +1151,14 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) if (optee_ffa_protmem_pool_init(optee, sec_caps)) pr_info("Protected memory service not available\n");

+ rc = tee_device_register(optee->teedev); + if (rc) + goto err_unregister_devices; + + rc = tee_device_register(optee->supp_teedev); + if (rc) + goto err_unregister_devices; + rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES); if (rc) goto err_unregister_devices; diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index b8a2bdac3208..51624443359b 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1849,14 +1849,6 @@ static int optee_probe(struct platform_device *pdev)

optee_set_dev_group(optee);

- rc = tee_device_register(optee->teedev); - if (rc) - goto err_unreg_supp_teedev; - - rc = tee_device_register(optee->supp_teedev); - if (rc) - goto err_unreg_supp_teedev; - optee_cq_init(&optee->call_queue, thread_count); optee_supp_init(&optee->supp); optee->smc.memremaped_shm = memremaped_shm; @@ -1916,6 +1908,14 @@ static int optee_probe(struct platform_device *pdev) if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) pr_info("dynamic shared memory is enabled\n");

+ rc = tee_device_register(optee->teedev); + if (rc) + goto err_disable_shm_cache; + + rc = tee_device_register(optee->supp_teedev); + if (rc) + goto err_disable_shm_cache; + rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES); if (rc) goto err_disable_shm_cache; @@ -1942,7 +1942,6 @@ static int optee_probe(struct platform_device *pdev) optee_shm_arg_cache_uninit(optee); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex); -err_unreg_supp_teedev: tee_device_unregister(optee->supp_teedev); err_unreg_teedev: tee_device_unregister(optee->teedev);