@chjara on my pet embedded system (amd64 running ancient 4.x Linux with 4gb ram) calling malloc(1mb) repeatedly runs for about 600,000 iterations, at which point the VSS is 586 GB and the RSS is 2.2 GB, then the kernel OOMs and kills it.
There's more than a GB used up during the process that doesn't get accounted to the hungry thread, which is an interesting bug.
At its peak, the /proc/<pid>/status says VmPTE: 759592 kB, almost a gig of in kernel data structures keeping track of my garbage...