The apparent leak seems to be proportional to innodb_buffer_pool_size
With innodb_buffer_pool_size = 128M it takes about 2-3 days for the kernel to run out of memory and kill/crash the mariadb node.
With innodb_buffer_pool_size = 1024M it takes about 2-3 hours for the kernel to run out of memory and kill/crash the mariadb node.
Please ask specifically for any/all details, logs, further tests etc. required to assist in investigation.
I'd also be happy to be directed to any related issues discussions etc. that googling has so far not revealed to me.
3 x gentoo linux vmware vm's with 8GB RAM allocted to each