Hi,

On a x86_64 VM with quite a lot of Wireguard traffic (~300 GB per day), I
am seeing a memory leak with wireguard 0.0.20171221-5.  System is Debian
stretch, kernel 4.9.65-3+deb9u2, wireguard package from unstable.

I have attached the memory usage reported by Munin over one month.  The
memleak is quite evident, and seems to happen in "slab_cache".  I realized
the issue today because the machine was completely unusable ("fork: cannot
allocate memory" with any command in a shell).

The machine was rebooted just at the point marked "Week 03" (for the
kernel upgrade for Meltdown, but wireguard was also upgraded), and it also
marks the beginning of the memleak.

To sum things up:

- no memleak: kernel 4.9.51-1, wireguard 0.0.20171011-1
- memleak: kernel 4.9.65-3+deb9u2, wireguard 0.0.20171221-5
- currently testing: kernel 4.9.65-3+deb9u2, wireguard 0.0.20180202-1

I will let you know if the memleak is still here with 0.0.20180202-1.

Baptiste