syzkaller on risc-v

[Tobias Klauser]

On 2020-06-30 at 14:48:31 +0200, Dmitry Vyukov <dvyukov at google.com> wrote:
[...]
> 6. I observed lots of what looks like user-space process memory
> corruptions. There included thousands of panics in our Go programs
> with things that I would consider "impossible", at least they did not
> come up before in our syzbot fuzzing. Also some Go runtime
> "impossible" crashes, e.g.:
> https://gist.githubusercontent.com/dvyukov/fb489ed93f7180621c71714ee07e53dc/raw/a7d2e98a56da17af2aec79c164cd3a8e154ecf5c/gistfile1.txt
> Maybe it's a known issue? Should we use tip instead of 1.14? Is it more stable?
> Though it's not necessary Go b/c kernel contains hundreds of memory
> corruptions and we observed kernel corrupting user-space processes
> routinely. This is especially true without KASAN because kernel
> corruptions are not caught early. However, the ratio and nature of
> crashes makes me suspect some issue in Go risc-v runtime.

I haven't seen any of these crashes myself when testing the syzkaller
port, but then again I only ran it for rather brief amounts of time
(~1h) on my laptop using the riscv defconfig and a few additional
configs enabled.

AFAIK Go tip has seen quite some improvments to its RISC-V port, so it
might be worth giving it (or Go 1.14beta1) a try.