GHSA-654X-CWWV-5J9C Pillow: Arrow export leaks stale heap memory when PILLOW_ALIGNMENT > 1

Summary When PILLOWALIGNMENT is set above 1, exporting an image to Arrow returns uninitialized heap memory mixed in with the pixel data. That memory can include pixels from images the process freed earlier. Details With an alignment above 1, the default allocator pads each row up to alignedlinesi...