Don't try to restore the terminal if we are not the foreground

process.  Otherwise, we may be stopped by SIGTTOU when we try to
update the terminal settings when cleaning up.

diff --git a/src/exec_pty.c b/src/exec_pty.c
index 93cc9b0d2011172c2d91c27126f83492a325d6d0..e301d97f53925dc4e67ed431b933c67d6100625b 100644 (file)
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -113,8 +113,11 @@ cleanup(int gotsignal)
 {
     debug_decl(cleanup, SUDO_DEBUG_EXEC);
 
-    if (!tq_empty(&io_plugins))
-       term_restore(io_fds[SFD_USERTTY], 0);
+    if (!tq_empty(&io_plugins) && io_fds[SFD_USERTTY] != -1) {
+       check_foreground();
+       if (foreground) {
+           term_restore(io_fds[SFD_USERTTY], 0);
+    }
 #ifdef HAVE_SELINUX
     selinux_restore_tty();
 #endif
@@ -680,9 +683,12 @@ pty_close(struct command_status *cstat)
     flush_output();
 
     if (io_fds[SFD_USERTTY] != -1) {
-       do {
-           n = term_restore(io_fds[SFD_USERTTY], 0);
-       } while (!n && errno == EINTR);
+       check_foreground();
+       if (foreground) {
+           do {
+               n = term_restore(io_fds[SFD_USERTTY], 0);
+           } while (!n && errno == EINTR);
+       }
     }
 
     /* If child was signalled, write the reason to stdout like the shell. */
@@ -1004,7 +1010,7 @@ exec_monitor(struct command_details *details, int backchannel)
                goto done;
            if (errno == EINTR)
                continue;
-           error(1, _("select failed"));
+           error(1, "monitor: %s", _("select failed"));
        }
 
        if (FD_ISSET(signal_pipe[0], fdsr)) {
@@ -1256,7 +1262,7 @@ safe_close(int fd)
     /* Avoid closing /dev/tty or std{in,out,err}. */
     if (fd < 3 || fd == io_fds[SFD_USERTTY]) {
        errno = EINVAL;
-       return -1;
+       debug_return_int(-1);
     }
     debug_return_int(close(fd));
 }