diff options
| -rw-r--r-- | docs/linux/kernel_configs.md | 7 | ||||
| -rw-r--r-- | docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md | 7 | ||||
| -rw-r--r-- | docs/linux/troubleshooting.md | 36 |
3 files changed, 50 insertions, 0 deletions
diff --git a/docs/linux/kernel_configs.md b/docs/linux/kernel_configs.md index ebd907955..b6dc311c2 100644 --- a/docs/linux/kernel_configs.md +++ b/docs/linux/kernel_configs.md @@ -65,6 +65,13 @@ It is recommended to disable the following config (and required if your kernel d # CONFIG_RANDOMIZE_BASE is not set ``` +It is also recommended to disable the Predictable Network Interface Names mechanism. This can be done +either via syzkaller configuration (see details [here](troubleshooting.md)) or by adjusting the following configs: +``` +CONFIG_CMDLINE_BOOL=y +CONFIG_CMDLINE="net.ifnames=0" +``` + ## Bug detection configs Syzkaller is meant to be used with diff --git a/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md b/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md index b54013199..7de20e6f5 100644 --- a/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md +++ b/docs/linux/setup_ubuntu-host_qemu-vm_x86-64-kernel.md @@ -61,6 +61,13 @@ Since enabling these options results in more sub options being available, we nee make CC="$GCC/bin/gcc" olddefconfig ``` +You might also be interested in disabling the Predictable Network Interface Names mechanism. This can be disabled either in the syzkaller configuration (see details [here](troubleshooting.md)) or by updating these kernel configuration parameters: + +``` +CONFIG_CMDLINE_BOOL=y +CONFIG_CMDLINE="net.ifnames=0" +``` + Build the kernel: ``` diff --git a/docs/linux/troubleshooting.md b/docs/linux/troubleshooting.md index 76f780fa4..3993dc1f6 100644 --- a/docs/linux/troubleshooting.md +++ b/docs/linux/troubleshooting.md @@ -27,6 +27,42 @@ Here are some things to check if there are problems running syzkaller. CONFIG_E1000=y CONFIG_E1000E=y ``` + - If the virtual machine reports that it has "Failed to start Raise network interfaces" or (which + is a consequence of that) syzkaller is unable to connect to the virtual machines, try to disable + the Predictable Network Interface Names mechanism. There are two ways to achieve this: + - Add the following two lines to the kernel configuration file and recompile the kernel. + ``` + CONFIG_CMDLINE_BOOL=y + CONFIG_CMDLINE="net.ifnames=0" + ``` + - Add the following line to the VM's properties inside the syzkaller manager configuration: + ``` + "cmdline": "net.ifnames=0" + ``` + + The resulting configuration may look like this: + ```json + { + "target": "linux/amd64", + "http": "127.0.0.1:56741", + "workdir": "$GOPATH/src/github.com/google/syzkaller/workdir", + "kernel_obj": "$KERNEL", + "image": "$IMAGE/stretch.img", + "sshkey": "$IMAGE/stretch.id_rsa", + "syzkaller": "$GOPATH/src/github.com/google/syzkaller", + "procs": 8, + "type": "qemu", + "vm": { + "count": 4, + "kernel": "$KERNEL/arch/x86/boot/bzImage", + "cmdline": "net.ifnames=0", + "cpu": 2, + "mem": 2048 + } + } + ``` + + This is, however, not guaranteed to work across all virtualization technologies. - Check that the `CONFIG_KCOV` option is available inside the VM: - `ls /sys/kernel/debug # Check debugfs mounted` |