firmware: qcom: uefisecapp: fix efivars registration race

JIRA: https://issues.redhat.com/browse/RHEL-117514

commit da8d493
Author: Johan Hovold <johan+linaro@kernel.org>
Date:   Mon Jan 20 16:10:00 2025 +0100

    firmware: qcom: uefisecapp: fix efivars registration race

    Since the conversion to using the TZ allocator, the efivars service is
    registered before the memory pool has been allocated, something which
    can lead to a NULL-pointer dereference in case of a racing EFI variable
    access.

    Make sure that all resources have been set up before registering the
    efivars.

    Fixes: 6612103 ("firmware: qcom: qseecom: convert to using the TZ allocator")
    Cc: stable@vger.kernel.org      # 6.11
    Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
    Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
    Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
    Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
    Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
    Link: https://lore.kernel.org/r/20250120151000.13870-1-johan+linaro@kernel.org
    Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Signed-off-by: Eric Chanudet <echanude@redhat.com>

Author: eric-ch

drivers/firmware/qcom/qcom_qseecom_uefisecapp.c

@@ -814,15 +814,6 @@ static int qcom_uefisecapp_probe(struct auxiliary_device *aux_dev,
 
 	qcuefi->client = container_of(aux_dev, struct qseecom_client, aux_dev);
 
-	auxiliary_set_drvdata(aux_dev, qcuefi);
-	status = qcuefi_set_reference(qcuefi);
-	if (status)
-		return status;
-
-	status = efivars_register(&qcuefi->efivars, &qcom_efivar_ops);
-	if (status)
-		qcuefi_set_reference(NULL);
-
 	memset(&pool_config, 0, sizeof(pool_config));
 	pool_config.initial_size = SZ_4K;
 	pool_config.policy = QCOM_TZMEM_POLICY_MULTIPLIER;
@@ -833,6 +824,15 @@ static int qcom_uefisecapp_probe(struct auxiliary_device *aux_dev,
 	if (IS_ERR(qcuefi->mempool))
 		return PTR_ERR(qcuefi->mempool);
 
+	auxiliary_set_drvdata(aux_dev, qcuefi);
+	status = qcuefi_set_reference(qcuefi);
+	if (status)
+		return status;
+
+	status = efivars_register(&qcuefi->efivars, &qcom_efivar_ops);
+	if (status)
+		qcuefi_set_reference(NULL);
+
 	return status;
 }