If not using a pty and the child process gets SIGTTOU or SIGTTIN

and sudo is the foreground process, make the child the foreground
process and continue it.

diff --git a/src/exec.c b/src/exec.c
index 8bc5555930c8df2fe241730d10b100c0a240a648..f70ad77f89ec4bfb59ab89c6efa9880d488d23c7 100644 (file)
--- a/src/exec.c
+++ b/src/exec.c
@@ -515,51 +515,69 @@ dispatch_signals(int sv[2], pid_t child, int log_io, struct command_status *csta
                     * select() notification.
                     */
                    (void) shutdown(sv[0], SHUT_WR);
-               } else {
-                   if (WIFSTOPPED(status)) {
+               } else if (WIFSTOPPED(status)) {
+                   /*
+                    * Save the controlling terminal's process group
+                    * so we can restore it after we resume, if needed.
+                    * Most well-behaved shells change the pgrp back to
+                    * its original value before suspending so we must
+                    * not try to restore in that case, lest we race with
+                    * the child upon resume, potentially stopping sudo
+                    * with SIGTTOU while the command continues to run.
+                    */
+                   sigaction_t sa, osa;
+                   pid_t saved_pgrp = (pid_t)-1;
+                   int signo = WSTOPSIG(status);
+                   int fd = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
+                   if (fd != -1) {
+                       saved_pgrp = tcgetpgrp(fd);
                        /*
-                        * Save the controlling terminal's process group
-                        * so we can restore it after we resume, if needed.
-                        * Most well-behaved shells change the pgrp back to
-                        * its original value before suspending so we must
-                        * not try to restore in that case, lest we race with
-                        * the child upon resume, potentially stopping sudo
-                        * with SIGTTOU while the command continues to run.
+                        * Child was stopped trying to access controlling
+                        * terminal.  If the child has a different pgrp
+                        * and we own the controlling terminal, give it
+                        * to the child's pgrp and let it continue.
                         */
-                       sigaction_t sa, osa;
-                       pid_t saved_pgrp = (pid_t)-1;
-                       int signo = WSTOPSIG(status);
-                       int fd = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
-                       if (fd != -1) {
-                           if ((saved_pgrp = tcgetpgrp(fd)) == ppgrp)
-                               saved_pgrp = -1;
-                       }
-                       if (signo == SIGTSTP) {
-                           memset(&sa, 0, sizeof(sa));
-                           sigemptyset(&sa.sa_mask);
-                           sa.sa_flags = SA_RESTART;
-                           sa.sa_handler = SIG_DFL;
-                           sudo_sigaction(SIGTSTP, &sa, &osa);
-                       }
-                       if (kill(getpid(), signo) != 0)
-                           warning("kill(%d, SIG%s)", (int)getpid(), signame);
-                       if (signo == SIGTSTP)
-                           sudo_sigaction(SIGTSTP, &osa, NULL);
-                       if (fd != -1) {
-                           /*
-                            * Restore command's process group if different.
-                            * Otherwise, we cannot resume some shells.
-                            */
-                           if (saved_pgrp != (pid_t)-1)
-                               (void)tcsetpgrp(fd, saved_pgrp);
-                           close(fd);
+                       if (signo == SIGTTOU || signo == SIGTTIN) {
+                           if (saved_pgrp == ppgrp) {
+                               pid_t child_pgrp = getpgid(child);
+                               if (child_pgrp != ppgrp) {
+                                   if (tcsetpgrp(fd, child_pgrp) == 0) {
+                                       if (killpg(child_pgrp, SIGCONT) != 0) {
+                                           warning("kill(%d, SIGCONT)",
+                                               (int)child_pgrp);
+                                       }
+                                       close(fd);
+                                       debug_return_int(1);
+                                   }
+                               }
+                           }
                        }
-                   } else {
-                       /* Child has exited, we are done. */
-                       cstat->type = CMD_WSTATUS;
-                       cstat->val = status;
-                       debug_return_int(0);
                    }
+                   if (signo == SIGTSTP) {
+                       memset(&sa, 0, sizeof(sa));
+                       sigemptyset(&sa.sa_mask);
+                       sa.sa_flags = SA_RESTART;
+                       sa.sa_handler = SIG_DFL;
+                       sudo_sigaction(SIGTSTP, &sa, &osa);
+                   }
+                   if (kill(getpid(), signo) != 0)
+                       warning("kill(%d, SIG%s)", (int)getpid(), signame);
+                   if (signo == SIGTSTP)
+                       sudo_sigaction(SIGTSTP, &osa, NULL);
+                   if (fd != -1) {
+                       /*
+                        * Restore command's process group if different.
+                        * Otherwise, we cannot resume some shells.
+                        */
+                       if (saved_pgrp != ppgrp)
+                           (void)tcsetpgrp(fd, saved_pgrp);
+                       close(fd);
+                   }
+               } else {
+                   /* Child has exited or been killed, we are done. */
+                   cstat->type = CMD_WSTATUS;
+                   cstat->val = status;
+                   debug_return_int(0);
                }
            }
        } else {