1 files changed, 34 insertions, 34 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
index 516ab9cf88fc..7f5abb03be1b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
@@ -140,13 +140,15 @@ static struct amdgpu_acpi_priv {
  * @atif: atif structure
  * @function: the ATIF function to execute
  * @params: ATIF function params
+ * @min_size: minimum size of the expected output buffer in bytes
  *
  * Executes the requested ATIF function (all asics).
  * Returns a pointer to the acpi output buffer.
  */
 static union acpi_object *amdgpu_atif_call(struct amdgpu_atif *atif,
 					   int function,
-					   struct acpi_buffer *params)
+					   struct acpi_buffer *params,
+					   size_t min_size)
 {
 	acpi_status status;
 	union acpi_object *obj;
@@ -189,6 +191,28 @@ static union acpi_object *amdgpu_atif_call(struct amdgpu_atif *atif,
 		return NULL;
 	}
 
+	if (obj->buffer.length < sizeof(u16)) {
+		DRM_DEBUG_DRIVER("ATIF buffer too small to hold size field: %u\n",
+				 obj->buffer.length);
+		kfree(obj);
+		return NULL;
+	}
+
+	if (obj->buffer.length < *(u16 *)obj->buffer.pointer) {
+		DRM_DEBUG_DRIVER("ATIF buffer length mismatch: reported %u, actual %u\n",
+				 *(u16 *)obj->buffer.pointer,
+				 obj->buffer.length);
+		kfree(obj);
+		return NULL;
+	}
+
+	if (*(u16 *)obj->buffer.pointer < min_size) {
+		DRM_DEBUG_DRIVER("ATIF buffer too small: expected %zu, got %u\n",
+				 min_size, *(u16 *)obj->buffer.pointer);
+		kfree(obj);
+		return NULL;
+	}
+
 	return obj;
 }
 
@@ -251,19 +275,14 @@ int amdgpu_atif_verify_interface(struct amdgpu_atif *atif)
 	size_t size;
 	int err = 0;
 
-	info = amdgpu_atif_call(atif, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
+	info = amdgpu_atif_call(atif, ATIF_FUNCTION_VERIFY_INTERFACE, NULL,
+				sizeof(output));
 	if (!info)
 		return -EIO;
 
 	memset(&output, 0, sizeof(output));
 
-	size = *(u16 *) info->buffer.pointer;
-	if (size < 12) {
-		DRM_INFO("ATIF buffer is too small: %zu\n", size);
-		err = -EINVAL;
-		goto out;
-	}
-	size = min(sizeof(output), size);
+	size = min(sizeof(output), (size_t)*(u16 *)info->buffer.pointer);
 
 	memcpy(&output, info->buffer.pointer, size);
 
@@ -273,7 +292,6 @@ int amdgpu_atif_verify_interface(struct amdgpu_atif *atif)
 	amdgpu_atif_parse_notification(&atif->notifications, output.notification_mask);
 	amdgpu_atif_parse_functions(&atif->functions, output.function_bits);
 
-out:
 	kfree(info);
 	return err;
 }
@@ -299,20 +317,14 @@ int amdgpu_atif_get_notification_params(struct amdgpu_atif *atif)
 	int err = 0;
 
 	info = amdgpu_atif_call(atif, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS,
-				NULL);
+				NULL, offsetof(struct atif_system_params, command_code));
 	if (!info) {
 		err = -EIO;
 		goto out;
 	}
 
-	size = *(u16 *) info->buffer.pointer;
-	if (size < 10) {
-		err = -EINVAL;
-		goto out;
-	}
-
 	memset(&params, 0, sizeof(params));
-	size = min(sizeof(params), size);
+	size = min(sizeof(params), (size_t)*(u16 *)info->buffer.pointer);
 	memcpy(&params, info->buffer.pointer, size);
 
 	DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
@@ -376,20 +388,14 @@ int amdgpu_atif_query_backlight_caps(struct amdgpu_atif *atif)
 
 	info = amdgpu_atif_call(atif,
 		ATIF_FUNCTION_QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS,
-		&params);
+		&params, offsetof(struct atif_qbtc_output, data_points));
 	if (!info) {
 		err = -EIO;
 		goto out;
 	}
 
-	size = *(u16 *) info->buffer.pointer;
-	if (size < 10) {
-		err = -EINVAL;
-		goto out;
-	}
-
 	memset(&characteristics, 0, sizeof(characteristics));
-	size = min(sizeof(characteristics), size);
+	size = min(sizeof(characteristics), (size_t)*(u16 *)info->buffer.pointer);
 	memcpy(&characteristics, info->buffer.pointer, size);
 
 	atif->backlight_caps.caps_valid = true;
@@ -427,24 +433,18 @@ static int amdgpu_atif_get_sbios_requests(struct amdgpu_atif *atif,
 	int count = 0;
 
 	info = amdgpu_atif_call(atif, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS,
-				NULL);
+				NULL, sizeof(*req));
 	if (!info)
 		return -EIO;
 
-	size = *(u16 *)info->buffer.pointer;
-	if (size < 0xd) {
-		count = -EINVAL;
-		goto out;
-	}
 	memset(req, 0, sizeof(*req));
 
-	size = min(sizeof(*req), size);
+	size = min(sizeof(*req), (size_t)*(u16 *)info->buffer.pointer);
 	memcpy(req, info->buffer.pointer, size);
 	DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);
 
 	count = hweight32(req->pending);
 
-out:
 	kfree(info);
 	return count;
 }