From 0d70df119539d818224b0d014602aaad2bd1b95e Mon Sep 17 00:00:00 2001 From: Daniel J Walsh Date: Mon, 28 Sep 2020 15:55:06 -0400 Subject: Ignore containers.conf sysctl when namespaces set to host If user sets namespace to host, then default sysctls need to be ignored that are specific to that namespace. --net=host ignore sysctls that begin with net. --ipc=host ignore fs.mqueue --uts=host ignore kernel.domainname and kernel.hostname Signed-off-by: Daniel J Walsh --- cmd/podman/common/create.go | 2 +- pkg/specgen/generate/security.go | 46 ++++++++++++++++++++++++++++++++++++++++ test/e2e/containers_conf_test.go | 6 ++++++ test/e2e/run_test.go | 5 +++++ 4 files changed, 58 insertions(+), 1 deletion(-) diff --git a/cmd/podman/common/create.go b/cmd/podman/common/create.go index bb4726817..4efdf1164 100644 --- a/cmd/podman/common/create.go +++ b/cmd/podman/common/create.go @@ -448,7 +448,7 @@ func GetCreateFlags(cf *ContainerCLIOpts) *pflag.FlagSet { createFlags.StringSliceVar( &cf.Sysctl, - "sysctl", containerConfig.Sysctls(), + "sysctl", []string{}, "Sysctl options", ) createFlags.StringVar( diff --git a/pkg/specgen/generate/security.go b/pkg/specgen/generate/security.go index 87e8029a7..7c818cf62 100644 --- a/pkg/specgen/generate/security.go +++ b/pkg/specgen/generate/security.go @@ -7,6 +7,7 @@ import ( "github.com/containers/common/pkg/capabilities" "github.com/containers/common/pkg/config" "github.com/containers/podman/v2/libpod" + "github.com/containers/podman/v2/libpod/define" "github.com/containers/podman/v2/libpod/image" "github.com/containers/podman/v2/pkg/specgen" "github.com/containers/podman/v2/pkg/util" @@ -167,7 +168,52 @@ func securityConfigureGenerator(s *specgen.SpecGenerator, g *generate.Generator, } g.SetRootReadonly(s.ReadOnlyFilesystem) + + // Add default sysctls + defaultSysctls, err := util.ValidateSysctls(rtc.Sysctls()) + if err != nil { + return err + } + for sysctlKey, sysctlVal := range defaultSysctls { + + // Ignore mqueue sysctls if --ipc=host + if s.IpcNS.IsHost() && strings.HasPrefix(sysctlKey, "fs.mqueue.") { + logrus.Infof("Sysctl %s=%s ignored in containers.conf, since IPC Namespace set to host", sysctlKey, sysctlVal) + + continue + } + + // Ignore net sysctls if --net=host + if s.NetNS.IsHost() && strings.HasPrefix(sysctlKey, "net.") { + logrus.Infof("Sysctl %s=%s ignored in containers.conf, since Network Namespace set to host", sysctlKey, sysctlVal) + continue + } + + // Ignore uts sysctls if --uts=host + if s.UtsNS.IsHost() && (strings.HasPrefix(sysctlKey, "kernel.domainname") || strings.HasPrefix(sysctlKey, "kernel.hostname")) { + logrus.Infof("Sysctl %s=%s ignored in containers.conf, since UTS Namespace set to host", sysctlKey, sysctlVal) + continue + } + + g.AddLinuxSysctl(sysctlKey, sysctlVal) + } + for sysctlKey, sysctlVal := range s.Sysctl { + + if s.IpcNS.IsHost() && strings.HasPrefix(sysctlKey, "fs.mqueue.") { + return errors.Wrapf(define.ErrInvalidArg, "sysctl %s=%s can't be set since IPC Namespace set to host", sysctlKey, sysctlVal) + } + + // Ignore net sysctls if --net=host + if s.NetNS.IsHost() && strings.HasPrefix(sysctlKey, "net.") { + return errors.Wrapf(define.ErrInvalidArg, "sysctl %s=%s can't be set since Host Namespace set to host", sysctlKey, sysctlVal) + } + + // Ignore uts sysctls if --uts=host + if s.UtsNS.IsHost() && (strings.HasPrefix(sysctlKey, "kernel.domainname") || strings.HasPrefix(sysctlKey, "kernel.hostname")) { + return errors.Wrapf(define.ErrInvalidArg, "sysctl %s=%s can't be set since UTS Namespace set to host", sysctlKey, sysctlVal) + } + g.AddLinuxSysctl(sysctlKey, sysctlVal) } diff --git a/test/e2e/containers_conf_test.go b/test/e2e/containers_conf_test.go index 02c5d1428..ddb62c327 100644 --- a/test/e2e/containers_conf_test.go +++ b/test/e2e/containers_conf_test.go @@ -179,6 +179,12 @@ var _ = Describe("Podman run", func() { session.WaitWithDefaultTimeout() Expect(session.ExitCode()).To(Equal(0)) Expect(session.OutputToString()).To(ContainSubstring("1000")) + + // Ignore containers.conf setting if --net=host + session = podmanTest.Podman([]string{"run", "--rm", "--net", "host", fedoraMinimal, "cat", "/proc/sys/net/ipv4/ping_group_range"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + Expect(session.OutputToString()).ToNot((ContainSubstring("1000"))) }) It("podman run containers.conf search domain", func() { diff --git a/test/e2e/run_test.go b/test/e2e/run_test.go index 5c28f18f2..5617f50b7 100644 --- a/test/e2e/run_test.go +++ b/test/e2e/run_test.go @@ -373,6 +373,11 @@ USER bin` session.WaitWithDefaultTimeout() Expect(session.ExitCode()).To(Equal(0)) Expect(session.OutputToString()).To(ContainSubstring("net.core.somaxconn = 65535")) + + // network sysctls should fail if --net=host is set + session = podmanTest.Podman([]string{"run", "--net", "host", "--rm", "--sysctl", "net.core.somaxconn=65535", ALPINE, "sysctl", "net.core.somaxconn"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(125)) }) It("podman run blkio-weight test", func() { -- cgit v1.2.3-54-g00ecf