[libcamera-devel] [PATCH v4] gstreamer: Add error checking in gst_libcamera_src_task_enter()

[Vedant Paranjape]

The return value from generateConfiguration() was not checked. Only assert
was added as a guard which checked if the size of generated camera config was
equal to size of roles passed to it.

If the roles variable has an invalid/unsupported role, it will return
a nullptr and then trying to access a member on a nullptr for size comparison
will result in a segmentation fault. So, if the function returns a nullptr,
it will simply push an error message on GstBus and gracefully exit.

Signed-off-by: Vedant Paranjape <vedantparanjape160201 at gmail.com>
---
 src/gstreamer/gstlibcamerasrc.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
index 87246b40..ccc61590 100644
--- a/src/gstreamer/gstlibcamerasrc.cpp
+++ b/src/gstreamer/gstlibcamerasrc.cpp
@@ -375,10 +375,13 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
 
 	/* Generate the stream configurations, there should be one per pad. */
 	state->config_ = state->cam_->generateConfiguration(roles);
-	/*
-	 * \todo Check if camera may increase or decrease the number of streams
-	 * regardless of the number of roles.
-	 */
+	if (state->config_ == nullptr) {
+		GST_ELEMENT_ERROR(self, RESOURCE, SETTINGS,
+				  ("Failed to generate camera configuration from roles"),
+				  ("Camera::generateConfiguration() returned nullptr"));
+		gst_task_stop(task);
+		return;
+	}
 	g_assert(state->config_->size() == state->srcpads_.size());
 
 	for (gsize i = 0; i < state->srcpads_.size(); i++) {
-- 
2.25.1