Please note that the gstallocator.c false positive warning issue has been fixed upstream (see link below). This warning was completely harmless.
As for the assertion, it’s often hit due to miss-implementation of buffer pool reset function. It was also broken until recently in the GstBufferPool base class. The consequence of this one would be that the pool fails to reset the buffer to it’s original size. In the good cases (and most case) the buffer will be discarded and given back to the allocator. This may lead to unwanted run-time allocation, even though V4L2 allocator is handling a memory pool mitigating this defect. In the bad case, a shorter buffer may be acquired from the pool, this would generally lead to errors, but should be rare.
I believe it has been recommended few times by NVidia to report upstream some issues. Be ware that we cannot deal with reported issues unless you do have way to reproduce that does not imply any forked code. We have analyzed NVidia GStreamer changes provided in a flat tarball and found that the amount of modified code is too important and the changes do not follow any of the upstream guidelines or even coding style requirement. We strongly encourage following an upstream work flow when enhancing GStreamer for your platform, this is the only way your users will fully benefit from upstream development.