1 files changed, 2 insertions, 7 deletions

diff --git a/src/firejail/join.c b/src/firejail/join.c
index fcc5e05d1..acd17366a 100644
--- a/src/firejail/join.c
+++ b/src/firejail/join.c
@@ -215,13 +215,8 @@ void join(pid_t pid, const char *homedir, int argc, char **argv, int index) {
         // check privileges for non-root users
         uid_t uid = getuid();
         if (uid != 0) {
-                struct stat s;
-                char *dir;
-                if (asprintf(&dir, "/proc/%u/ns", pid) == -1)
-                        errExit("asprintf");
-                if (stat(dir, &s) < 0)
-                        errExit("stat");
-                if (s.st_uid != uid) {
+                uid_t sandbox_uid = pid_get_uid(pid);
+                if (uid != sandbox_uid) {
                         fprintf(stderr, "Error: permission is denied to join a sandbox created by a different user.\n");
                         exit(1);
                 }