1 files changed, 9 insertions, 1 deletions

diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index a75eafbd3..ed1f86f0c 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -253,11 +253,19 @@ void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv)
         if (!(flags & DAEMON_ONLY_SANITIZE)) {
                 if (fork_or_rexec(argv))
                         exit(EXIT_SUCCESS); /* parent */
-                /* if daemonizing, make sure we detach from stdio & ctty */
+                /* if daemonizing, detach from stdio & ctty */
                 setsid();
                 dup2(fd, 0);
                 dup2(fd, 1);
                 dup2(fd, 2);
+                if (flags & DAEMON_DOUBLE_FORK) {
+                        /* On Linux, session leader can acquire ctty
+                         * unknowingly, by opening a tty.
+                         * Prevent this: stop being a session leader.
+                         */
+                        if (fork_or_rexec(argv))
+                                exit(EXIT_SUCCESS); /* parent */
+                }
         }
         while (fd > 2) {
                 close(fd--);