2 files changed, 35 insertions, 10 deletions
diff --git a/pkg/rootless/rootless_linux.c b/pkg/rootless/rootless_linux.c
index e5f9e88d9..4d8443fcb 100644
--- a/pkg/rootless/rootless_linux.c
+++ b/pkg/rootless/rootless_linux.c
@@ -465,38 +465,43 @@ reexec_in_user_namespace_wait (int pid, int options)
 static int
 create_pause_process (const char *pause_pid_file_path, char **argv)
 {
-  int r, p[2];
+  pid_t pid;
+  int p[2];
 
   if (pipe (p) < 0)
-    _exit (EXIT_FAILURE);
+    return -1;
 
-  r = fork ();
-  if (r < 0)
-    _exit (EXIT_FAILURE);
+  pid = fork ();
+  if (pid < 0)
+    {
+      close (p[0]);
+      close (p[1]);
+      return -1;
+    }
 
-  if (r)
+  if (pid)
     {
       char b;
+      int r;
 
       close (p[1]);
       /* Block until we write the pid file.  */
       r = TEMP_FAILURE_RETRY (read (p[0], &b, 1));
       close (p[0]);
 
-      reexec_in_user_namespace_wait (r, 0);
+      reexec_in_user_namespace_wait (pid, 0);
 
       return r == 1 && b == '0' ? 0 : -1;
     }
   else
     {
-      int fd;
-      pid_t pid;
+      int r, fd;
 
       close (p[0]);
 
       setsid ();
       pid = fork ();
-      if (r < 0)
+      if (pid < 0)
         _exit (EXIT_FAILURE);
 
       if (pid)
diff --git a/pkg/rootless/rootless_linux.go b/pkg/rootless/rootless_linux.go
index f76eab0e3..9ef56acb4 100644
--- a/pkg/rootless/rootless_linux.go
+++ b/pkg/rootless/rootless_linux.go
@@ -14,11 +14,13 @@ import (
 	"os/user"
 	"runtime"
 	"strconv"
+	"strings"
 	"sync"
 	"unsafe"
 
 	"github.com/containers/podman/v3/pkg/errorhandling"
 	"github.com/containers/storage/pkg/idtools"
+	pmount "github.com/containers/storage/pkg/mount"
 	"github.com/containers/storage/pkg/unshare"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -235,6 +237,24 @@ func becomeRootInUserNS(pausePid, fileToRead string, fileOutput *os.File) (_ boo
 		return false, 0, nil
 	}
 
+	if mounts, err := pmount.GetMounts(); err == nil {
+		for _, m := range mounts {
+			if m.Mountpoint == "/" {
+				isShared := false
+				for _, o := range strings.Split(m.Optional, ",") {
+					if strings.HasPrefix(o, "shared:") {
+						isShared = true
+						break
+					}
+				}
+				if !isShared {
+					logrus.Warningf("%q is not a shared mount, this could cause issues or missing mounts with rootless containers", m.Mountpoint)
+				}
+				break
+			}
+		}
+	}
+
 	cPausePid := C.CString(pausePid)
 	defer C.free(unsafe.Pointer(cPausePid))