6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shao-Fu Chen commit c108feca0a096f8db25d1b69130035025e9e936d upstream. 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 [JW: adding fixes and cc] Signed-off-by: Jens Wiklander Signed-off-by: Greg Kroah-Hartman --- drivers/tee/optee/ffa_abi.c | 16 ++++++++-------- drivers/tee/optee/smc_abi.c | 17 ++++++++--------- 2 files changed, 16 insertions(+), 17 deletions(-) --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -1094,14 +1094,6 @@ static int optee_ffa_probe(struct ffa_de 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; @@ -1130,6 +1122,14 @@ static int optee_ffa_probe(struct ffa_de 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; --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1840,14 +1840,6 @@ static int optee_probe(struct platform_d 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; @@ -1907,6 +1899,14 @@ static int optee_probe(struct platform_d 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; @@ -1933,7 +1933,6 @@ err_supp_uninit: 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);