Enabling BPFLSM based KSP protection on Kubearmor itself

KubeArmor/BPF/enforcer.bpf.c

@@ -75,7 +75,10 @@ int BPF_PROG(enforce_proc, struct linux_binprm *bprm, int ret) {
   if (src_offset == NULL)
     fromSourceCheck = false;
 
-  void *src_ptr = &src_buf->buf[*src_offset];
+  void *src_ptr;
+  if (src_buf->buf[*src_offset]) {
+    src_ptr = &src_buf->buf[*src_offset];
+  }
   if (src_ptr == NULL)
     fromSourceCheck = false;
 
@@ -152,10 +155,9 @@ int BPF_PROG(enforce_proc, struct linux_binprm *bprm, int ret) {
     goto decision;
   }
 
-
   // match exec name
   struct qstr d_name;
-  d_name = BPF_CORE_READ(f_path.dentry,d_name);
+  d_name = BPF_CORE_READ(f_path.dentry, d_name);
   bpf_map_update_elem(&bufk, &two, z, BPF_ANY);
   bpf_probe_read_str(pk->path, MAX_STRING_SIZE, d_name.name);
 

KubeArmor/BPF/shared.h

@@ -272,6 +272,9 @@ static inline void get_outer_key(struct outer_key *pokey,
                                  struct task_struct *t) {
   pokey->pid_ns = get_task_pid_ns_id(t);
   pokey->mnt_ns = get_task_mnt_ns_id(t);
+  // TODO: Use cgroup ns as well for host process identification to support enforcement on deployments using hostpidns
+  // u32 cg_ns = BPF_CORE_READ(t, nsproxy, cgroup_ns, ns).inum;
+  // if (pokey->pid_ns == PROC_PID_INIT_INO && cg_ns == PROC_CGROUP_INIT_INO) {
   if (pokey->pid_ns == PROC_PID_INIT_INO) {
     pokey->pid_ns = 0;
     pokey->mnt_ns = 0;
@@ -288,20 +291,13 @@ static __always_inline u32 init_context(event *event_data) {
   event_data->host_ppid = get_task_ppid(task);
   event_data->host_pid = bpf_get_current_pid_tgid() >> 32;
 
-  u32 pid = get_task_ns_tgid(task);
-  if (event_data->host_pid == pid) { // host
-    event_data->pid_id = 0;
-    event_data->mnt_id = 0;
-
-    event_data->ppid = get_task_ppid(task);
-    event_data->pid = bpf_get_current_pid_tgid() >> 32;
-  } else { // container
-    event_data->pid_id = get_task_pid_ns_id(task);
-    event_data->mnt_id = get_task_mnt_ns_id(task);
+  struct outer_key okey;
+  get_outer_key(&okey, task);
+  event_data->pid_id = okey.pid_ns;
+  event_data->mnt_id = okey.mnt_ns;
 
-    event_data->ppid = get_task_ns_ppid(task);
-    event_data->pid = pid;
-  }
+  event_data->ppid = get_task_ppid(task);
+  event_data->pid =  get_task_ns_tgid(task);
 
   event_data->uid = bpf_get_current_uid_gid();
 
@@ -487,10 +483,15 @@ static inline int match_and_enforce_path_hooks(struct path *f_path, u32 id,
   if (src_offset == NULL)
     fromSourceCheck = false;
 
-  void *ptr = &src_buf->buf[*src_offset];
+  void *src_ptr;
+  if (src_buf->buf[*src_offset]) {
+    src_ptr = &src_buf->buf[*src_offset];
+  }
+  if (src_ptr == NULL)
+    fromSourceCheck = false;
 
   if (fromSourceCheck) {
-    bpf_probe_read_str(store->source, MAX_STRING_SIZE, ptr);
+    bpf_probe_read_str(store->source, MAX_STRING_SIZE, src_ptr);
 
     val = bpf_map_lookup_elem(inner, store);
 

KubeArmor/config/config.go

@@ -60,6 +60,8 @@ type KubearmorConfig struct {
 	MaxAlertPerSec    int  // Maximum alerts allowed per second
 	ThrottleSec       int  // Number of seconds for which subsequent alerts will be dropped
 	AnnotateResources bool // enable annotations by kubearmor if kubearmor-controller is not present
+
+	ProcFsMount string // path where procfs is hosted
 }
 
 // GlobalCfg Global configuration for Kubearmor
@@ -105,6 +107,7 @@ const (
 	ConfigMaxAlertPerSec                 string = "maxAlertPerSec"
 	ConfigThrottleSec                    string = "throttleSec"
 	ConfigAnnotateResources              string = "annotateResources"
+	ConfigProcFsMount                    string = "procfsMount"
 )
 
 func readCmdLineParams() {
@@ -161,6 +164,8 @@ func readCmdLineParams() {
 
 	annotateResources := flag.Bool(ConfigAnnotateResources, false, "for kubearmor deployment without kubearmor-controller")
 
+	procFsMount := flag.String(ConfigProcFsMount, "/proc", "Path to the BPF filesystem to use for storing maps")
+
 	flags := []string{}
 	flag.VisitAll(func(f *flag.Flag) {
 		kv := fmt.Sprintf("%s:%v", f.Name, f.Value)
@@ -222,6 +227,8 @@ func readCmdLineParams() {
 	viper.SetDefault(ConfigThrottleSec, *throttleSec)
 
 	viper.SetDefault(ConfigAnnotateResources, *annotateResources)
+
+	viper.SetDefault(ConfigProcFsMount, *procFsMount)
 }
 
 // LoadConfig Load configuration
@@ -322,6 +329,8 @@ func LoadConfig() error {
 	GlobalCfg.ThrottleSec = viper.GetInt(ConfigThrottleSec)
 	GlobalCfg.AnnotateResources = viper.GetBool(ConfigAnnotateResources)
 
+	GlobalCfg.ProcFsMount = viper.GetString(ConfigProcFsMount)
+
 	kg.Printf("Final Configuration [%+v]", GlobalCfg)
 
 	return nil

KubeArmor/core/containerdHandler.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -193,13 +194,13 @@ func (ch *ContainerdHandler) GetContainerInfo(ctx context.Context, containerID s
 
 		pid := strconv.Itoa(int(taskRes.Processes[0].Pid))
 
-		if data, err := os.Readlink("/proc/" + pid + "/ns/pid"); err == nil {
+		if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/pid")); err == nil {
 			if _, err := fmt.Sscanf(data, "pid:[%d]\n", &container.PidNS); err != nil {
 				kg.Warnf("Unable to get PidNS (%s, %s, %s)", containerID, pid, err.Error())
 			}
 		}
 
-		if data, err := os.Readlink("/proc/" + pid + "/ns/mnt"); err == nil {
+		if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/mnt")); err == nil {
 			if _, err := fmt.Sscanf(data, "mnt:[%d]\n", &container.MntNS); err != nil {
 				kg.Warnf("Unable to get MntNS (%s, %s, %s)", containerID, pid, err.Error())
 			}

KubeArmor/core/crioHandler.go

@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strconv"
 	"time"
 
@@ -130,15 +131,15 @@ func (ch *CrioHandler) GetContainerInfo(ctx context.Context, containerID string,
 
 	pid := strconv.Itoa(containerInfo.Pid)
 
-	if data, err := os.Readlink("/proc/" + pid + "/ns/pid"); err == nil {
+	if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/pid")); err == nil {
 		if _, err := fmt.Sscanf(data, "pid:[%d]\n", &container.PidNS); err != nil {
 			kg.Warnf("Unable to get PidNS (%s, %s, %s)", containerID, pid, err.Error())
 		}
 	} else {
 		return container, err
 	}
 
-	if data, err := os.Readlink("/proc/" + pid + "/ns/mnt"); err == nil {
+	if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/mnt")); err == nil {
 		if _, err := fmt.Sscanf(data, "mnt:[%d]\n", &container.MntNS); err != nil {
 			kg.Warnf("Unable to get MntNS (%s, %s, %s)", containerID, pid, err.Error())
 		}

KubeArmor/core/dockerHandler.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"path/filepath"
 	"slices"
 	"strconv"
 	"strings"
@@ -144,13 +145,13 @@ func (dh *DockerHandler) GetContainerInfo(containerID string, OwnerInfo map[stri
 
 	pid := strconv.Itoa(inspect.State.Pid)
 
-	if data, err := os.Readlink("/proc/" + pid + "/ns/pid"); err == nil {
+	if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/pid")); err == nil {
 		if _, err := fmt.Sscanf(data, "pid:[%d]\n", &container.PidNS); err != nil {
 			kg.Warnf("Unable to get PidNS (%s, %s, %s)", containerID, pid, err.Error())
 		}
 	}
 
-	if data, err := os.Readlink("/proc/" + pid + "/ns/mnt"); err == nil {
+	if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, pid, "/ns/mnt")); err == nil {
 		if _, err := fmt.Sscanf(data, "mnt:[%d]\n", &container.MntNS); err != nil {
 			kg.Warnf("Unable to get MntNS (%s, %s, %s)", containerID, pid, err.Error())
 		}

KubeArmor/core/kubeUpdate.go

@@ -731,9 +731,9 @@ func (dm *KubeArmorDaemon) WatchK8sPods() {
 				}
 
 				// exception: kubearmor
-				if _, ok := pod.Labels["kubearmor-app"]; ok {
-					pod.Annotations["kubearmor-policy"] = "audited"
-				}
+				// if _, ok := pod.Labels["kubearmor-app"]; ok {
+				// 	pod.Annotations["kubearmor-policy"] = "audited"
+				// }
 
 				// == Visibility == //
 

KubeArmor/enforcer/appArmorEnforcer.go

@@ -114,11 +114,11 @@ profile apparmor-default flags=(attach_disconnected,mediate_deleted) {
 
 	existingProfiles := []string{}
 
-	if pids, err := os.ReadDir(filepath.Clean("/proc")); err == nil {
+	if pids, err := os.ReadDir(filepath.Clean(cfg.GlobalCfg.ProcFsMount)); err == nil {
 		for _, f := range pids {
 			if f.IsDir() {
 				if _, err := strconv.Atoi(f.Name()); err == nil {
-					if content, err := os.ReadFile(filepath.Clean("/proc/" + f.Name() + "/attr/current")); err == nil {
+					if content, err := os.ReadFile(filepath.Clean(cfg.GlobalCfg.ProcFsMount + "/" + f.Name() + "/attr/current")); err == nil {
 						line := strings.Split(string(content), "\n")[0]
 						words := strings.Split(line, " ")
 

KubeArmor/enforcer/bpflsm/enforcer.go

@@ -23,8 +23,8 @@ import (
 	tp "github.com/kubearmor/KubeArmor/KubeArmor/types"
 )
 
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang enforcer ../../BPF/enforcer.bpf.c -- -I/usr/include/ -O2 -g
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang enforcer_path ../../BPF/enforcer_path.bpf.c -- -I/usr/include/ -O2 -g
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang enforcer ../../BPF/enforcer.bpf.c -- -I/usr/include/ -O2 -g -fno-stack-protector
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -cc clang enforcer_path ../../BPF/enforcer_path.bpf.c -- -I/usr/include/ -O2 -g -fno-stack-protector
 
 // ===================== //
 // == BPFLSM Enforcer == //

KubeArmor/main_test.go

@@ -13,7 +13,7 @@ import (
 
 var clusterPtr, gRPCPtr, logPathPtr *string
 var enableKubeArmorPolicyPtr, enableKubeArmorHostPolicyPtr, enableKubeArmorVMPtr, coverageTestPtr, enableK8sEnv, tlsEnabled *bool
-var defaultFilePosturePtr, defaultCapabilitiesPosturePtr, defaultNetworkPosturePtr, hostDefaultCapabilitiesPosturePtr, hostDefaultNetworkPosturePtr, hostDefaultFilePosturePtr *string
+var defaultFilePosturePtr, defaultCapabilitiesPosturePtr, defaultNetworkPosturePtr, hostDefaultCapabilitiesPosturePtr, hostDefaultNetworkPosturePtr, hostDefaultFilePosturePtr, procFsMountPtr *string
 
 func init() {
 	// options (string)
@@ -32,6 +32,8 @@ func init() {
 	hostDefaultNetworkPosturePtr = flag.String("hostDefaultNetworkPosture", "block", "configuring default enforcement action in global network context {allow|audit|block}")
 	hostDefaultCapabilitiesPosturePtr = flag.String("hostDefaultCapabilitiesPosture", "block", "configuring default enforcement action in global capability context {allow|audit|block}")
 
+	procFsMountPtr = flag.String("procfsMount", "/proc", "Path to the BPF filesystem to use for storing maps")
+
 	// options (boolean)
 	enableKubeArmorPolicyPtr = flag.Bool("enableKubeArmorPolicy", true, "enabling KubeArmorPolicy")
 	enableKubeArmorHostPolicyPtr = flag.Bool("enableKubeArmorHostPolicy", true, "enabling KubeArmorHostPolicy")
@@ -42,6 +44,7 @@ func init() {
 
 	// options (boolean)
 	coverageTestPtr = flag.Bool("coverageTest", false, "enabling CoverageTest")
+
 }
 
 // TestMain - test to drive external testing coverage
@@ -64,6 +67,7 @@ func TestMain(t *testing.T) {
 		fmt.Sprintf("-enableKubeArmorHostPolicy=%s", strconv.FormatBool(*enableKubeArmorHostPolicyPtr)),
 		fmt.Sprintf("-coverageTest=%s", strconv.FormatBool(*coverageTestPtr)),
 		fmt.Sprintf("-tlsEnabled=%s", strconv.FormatBool(*tlsEnabled)),
+		fmt.Sprintf("-procfsMount=%s", *procFsMountPtr),
 	}
 
 	t.Log("[INFO] Executed KubeArmor")

KubeArmor/monitor/processTree.go

@@ -5,6 +5,7 @@ package monitor
 
 import (
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
@@ -231,7 +232,7 @@ func (mon *SystemMonitor) GetParentExecPath(containerID string, ctx SyscallConte
 
 	if readlink {
 		// just in case that it couldn't still get the full path
-		if data, err := os.Readlink("/proc/" + strconv.FormatUint(uint64(ctx.HostPPID), 10) + "/exe"); err == nil && data != "" && data != "/" {
+		if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, strconv.FormatUint(uint64(ctx.HostPPID), 10), "/exe")); err == nil && data != "" && data != "/" {
 			// // Store it in the ActiveHostPidMap so we don't need to read procfs again
 			// // We don't call BuildPidNode Here cause that will put this into a cyclic function call loop
 			// if pidMap, ok := ActiveHostPidMap[containerID]; ok {
@@ -276,7 +277,7 @@ func (mon *SystemMonitor) GetExecPath(containerID string, ctx SyscallContext, re
 
 	if readlink {
 		// just in case that it couldn't still get the full path
-		if data, err := os.Readlink("/proc/" + strconv.FormatUint(uint64(ctx.HostPID), 10) + "/exe"); err == nil && data != "" && data != "/" {
+		if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, strconv.FormatUint(uint64(ctx.HostPID), 10), "/exe")); err == nil && data != "" && data != "/" {
 			// // Store it in the ActiveHostPidMap so we don't need to read procfs again
 			// if pidMap, ok := ActiveHostPidMap[containerID]; ok {
 			// 	if node, ok := pidMap[ctx.HostPID]; ok {
@@ -318,7 +319,7 @@ func (mon *SystemMonitor) GetCommand(containerID string, ctx SyscallContext, rea
 
 	if readlink {
 		// just in case that it couldn't still get the full path
-		if data, err := os.Readlink("/proc/" + strconv.FormatUint(uint64(ctx.HostPID), 10) + "/exe"); err == nil && data != "" && data != "/" {
+		if data, err := os.Readlink(filepath.Join(cfg.GlobalCfg.ProcFsMount, strconv.FormatUint(uint64(ctx.HostPID), 10), "/exe")); err == nil && data != "" && data != "/" {
 			return data
 		} else if err != nil {
 			mon.Logger.Debugf("Could not read path from procfs due to %s", err.Error())

deployments/get/objects.go

@@ -264,6 +264,7 @@ func GenerateDaemonSet(env, namespace string) *appsv1.DaemonSet {
 	var terminationGracePeriodSeconds = int64(60)
 	var args = []string{
 		"-gRPC=" + strconv.Itoa(int(port)),
+		"-procfsMount=/host/procfs",
 	}
 
 	var containerVolumeMounts = []corev1.VolumeMount{
@@ -381,7 +382,6 @@ func GenerateDaemonSet(env, namespace string) *appsv1.DaemonSet {
 							Operator: "Exists",
 						},
 					},
-					HostPID:       true,
 					HostNetwork:   true,
 					RestartPolicy: "Always",
 					DNSPolicy:     "ClusterFirstWithHostNet",

pkg/KubeArmorOperator/common/defaults.go

@@ -237,13 +237,27 @@ var CommonVolumes = []corev1.Volume{
 			},
 		},
 	},
+	{
+		Name: "proc-fs-mount",
+		VolumeSource: corev1.VolumeSource{
+			HostPath: &corev1.HostPathVolumeSource{
+				Path: "/proc",
+				Type: &HostPathDirectory,
+			},
+		},
+	},
 }
 
 var CommonVolumesMount = []corev1.VolumeMount{
 	{
 		Name:      "sys-kernel-debug-path",
 		MountPath: "/sys/kernel/debug",
 	},
+	{
+		Name:      "proc-fs-mount",
+		MountPath: "/host/procfs",
+		ReadOnly:  true,
+	},
 }
 
 var KubeArmorCaVolume = []corev1.Volume{