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diff --git a/docs/netbsd.md b/docs/netbsd.md new file mode 100644 index 000000000..bc40acfc7 --- /dev/null +++ b/docs/netbsd.md @@ -0,0 +1,99 @@ +# NetBSD + +## How to run syzkaller on NetBSD using qemu + +So far the process is tested only on linux/amd64 host. To build Go binaries do: +``` +make TARGETOS=netbsd +``` +To build C `syz-executor` binary, copy `executor/*` files to a NetBSD machine and build there with: +``` +gcc executor/executor_NetBSD.cc -o syz-executor -O1 -lpthread -DGOOS=\"netbsd\" -DGIT_REVISION=\"CURRENT_GIT_REVISION\" +``` +Then, copy out the binary back to host into `bin/netbsd_amd64` dir. + +Building/running on a NetBSD host should work as well, but currently our `Makefile` does not work there, so you will need to do its work manually. + +Then, you need a NetBSD image with root ssh access with a key. General instructions can be found here [qemu instructions](https://wiki.qemu.org/Hosts/BSD). + +To prepare the image, use `anita`. (You need the python module `pexpect` installed, for using Anita) +``` +git clone https://github.com/utkarsh009/anita +python anita/anita --workdir anitatemp install http://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-8/201710221410Z/amd64/ +``` +Then spin up an instance from the image generated inside `./anitatemp` directory +``` +qemu-system-x86_64 -m 1024 -drive file=anitatemp/wd0.img,format=raw,media=disk -netdev user,id=mynet0,host=10.0.2.10,hostfwd=tcp:127.0.0.1:10022-:22 -device e1000,netdev=mynet0 -nographic +``` +Then create an ssh-keypair without a password and save it by the name, say, `netbsdkey` + +``` +ssh-keygen -t rsa +``` +Then append the following to `/etc/rc.conf` +``` +sshd=YES +ifconfig_wm0="inet 10.0.2.15 netmask 255.255.255.0" +``` +Append this to `/etc/ssh/sshd_config` +``` +Port 22 +ListenAddress 10.0.2.15 +``` +Then add your pubkey to `/root/.ssh/authorized_keys` and `reboot` the VM. +When you see the login prompt, open up another terminal on host and issue the following command +``` +ssh -i netbsd -p 10022 root@127.0.0.1 +``` + +If all of the above worked, `poweroff` the VM and create `netbsd.cfg` config file with the following contents (alter paths as necessary): +``` +{ + "name": "netbsd", + "target": "netbsd/amd64", + "http": ":10000", + "workdir": "work", + "syzkaller": "$GOPATH/src/github.com/google/syzkaller", + "image": "anitatemp/wd0.img", + "sshkey": "/path/to/netbsdkey", + "sandbox": "none", + "procs": 2, + "type": "qemu", + "vm": { + "qemu": "qemu-system-x86_64", + "count": 2, + "cpu": 2, + "mem": 2048 + } +} +``` + +Then, start `syz-manager` with: +``` +bin/syz-manager -config netbsd.cfg +``` +It should start printing output along the lines of: +``` +booting test machines... +wait for the connection from test machine... +machine check: 253 calls enabled, kcov=true, kleakcheck=false, faultinjection=false, comps=false +executed 3622, cover 1219, crashes 0, repro 0 +executed 7921, cover 1239, crashes 0, repro 0 +executed 32807, cover 1244, crashes 0, repro 0 +executed 35803, cover 1248, crashes 0, repro 0 +``` +If something does not work, add `-debug` flag to `syz-manager`. + +## Missing things + +- Automating the configuation changes (like appending to config files), generating the json config file on the fly (with customizable values to the keys using command line parameters) and calling syz-manager with `anita` using just a single command. +- Coverage. `executor/executor_netbsd.cc` uses a very primitive fallback for coverage. We need KCOV for NetBSD. It will also help to assess what's covered and what's missing. +- System call descriptions. `sys/netbsd/*.txt` is a dirty copy from `sys/linux/*.txt` with everything that does not compile dropped. We need to go through syscalls and verify/fix/extend them, including devices/ioctls/etc. +- Currently only `amd64` arch is supported. Supporting `386` would be useful, because it should cover compat paths. Also, we could do testing of the linux-compatibility subsystem. +- `pkg/csource` needs to be taught how to generate/build C reproducers. +- `pkg/host` needs to be taught how to detect supported syscalls/devices. +- `pkg/report`/`pkg/symbolizer` need to be taught how to extract/symbolize kernel crash reports. +- We need to learn how to build/use debug version of kernel. +- KASAN for NetBSD would be useful. +- On Linux we have emission of exernal networking/USB traffic into kernel using tun/gadgetfs. Implementing these for NetBSD could uncover a number of high-profile bugs. +- Last but not least, we need to support NetBSD in `syz-ci` command (including building kernel/image continuously from git). |