From be31207f6eb886170fd7505bd3ff54344d922297 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= Date: Wed, 13 Jul 2022 10:31:37 +0200 Subject: [PATCH] clh: Don't crash if no network device is set by the upper layer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit `ctr` doesn't set a network device when creating the sandbox, which leads to Cloud Hypervisor's driver crashing, see the log below: ``` panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x55641c23b248] goroutine 32 [running]: github.com/kata-containers/kata-containers/src/runtime/virtcontainers.glob..func1(0xc000397900) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/clh.go:163 +0x128 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*cloudHypervisor).vmAddNetPut(...) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/clh.go:1348 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*cloudHypervisor).bootVM(0xc000397900, {0x55641c76dfc0, 0xc000454ae0}) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/clh.go:1378 +0x5a2 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*cloudHypervisor).StartVM(0xc000397900, {0x55641c76dff8, 0xc00044c240}, 0x55641b8016fd) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/clh.go:659 +0x7ee github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*Sandbox).startVM.func2() /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/sandbox.go:1219 +0x190 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*LinuxNetwork).Run.func1({0xc0004a8910, 0x3b}) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/network_linux.go:319 +0x1b github.com/kata-containers/kata-containers/src/runtime/virtcontainers.doNetNS({0xc000048440, 0xc00044c240}, 0xc0005d5b38) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/network_linux.go:1045 +0x163 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*LinuxNetwork).Run(0xc000150c80, {0x55641c76dff8, 0xc00044c240}, 0xc00014e4e0) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/network_linux.go:318 +0x105 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*Sandbox).startVM(0xc000107d40, {0x55641c76dff8, 0xc0005529f0}) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/sandbox.go:1205 +0x65f github.com/kata-containers/kata-containers/src/runtime/virtcontainers.createSandboxFromConfig({_, _}, {{0x0, 0x0, 0x0}, {0xc000385a00, 0x1, 0x1}, {0x55641d033260, 0x0, ...}, ...}, ...) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/api.go:91 +0x346 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.CreateSandbox({_, _}, {{0x0, 0x0, 0x0}, {0xc000385a00, 0x1, 0x1}, {0x55641d033260, 0x0, ...}, ...}, ...) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/api.go:51 +0x150 github.com/kata-containers/kata-containers/src/runtime/virtcontainers.(*VCImpl).CreateSandbox(_, {_, _}, {{0x0, 0x0, 0x0}, {0xc000385a00, 0x1, 0x1}, {0x55641d033260, ...}, ...}) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/virtcontainers/implementation.go:35 +0x74 github.com/kata-containers/kata-containers/src/runtime/pkg/katautils.CreateSandbox({_, _}, {_, _}, {{0xc0004806c0, 0x9}, 0xc000140110, 0xc00000f7a0, {0x0, 0x0}, ...}, ...) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/pkg/katautils/create.go:175 +0x8b6 github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2.create({0x55641c76dff8, 0xc0004129f0}, 0xc00034a000, 0xc00036a000) /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2/create.go:147 +0xdea github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2.(*service).Create.func2() /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2/service.go:401 +0x32 created by github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2.(*service).Create /home/ubuntu/go/src/github.com/kata-containers/kata-containers/src/runtime/pkg/containerd-shim-v2/service.go:400 +0x534 ``` This bug has been introduced as part of the https://github.com/kata-containers/kata-containers/pull/4312 PR, which changed how we add the network device. In order to avoid the crash, let's simply check whether we have a device to be added before iterating the list of network devices. Fixes: #4618 Signed-off-by: Fabiano Fidêncio --- src/runtime/virtcontainers/clh.go | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/runtime/virtcontainers/clh.go b/src/runtime/virtcontainers/clh.go index 82c03fa02..aaa8e2886 100644 --- a/src/runtime/virtcontainers/clh.go +++ b/src/runtime/virtcontainers/clh.go @@ -149,6 +149,11 @@ func (c *clhClientApi) VmRemoveDevicePut(ctx context.Context, vmRemoveDevice chc // This is done in order to be able to override such a function as part of // our unit tests, as when testing bootVM we're on a mocked scenario already. var vmAddNetPutRequest = func(clh *cloudHypervisor) error { + if clh.netDevices == nil { + clh.Logger().Info("No network device has been configured by the upper layer") + return nil + } + addr, err := net.ResolveUnixAddr("unix", clh.state.apiSocket) if err != nil { return err