If waitpid() returns 0 or -1, display a warning, this should never happen.

Add a check for unhandled wait status (also should never happen).

diff --git a/src/exec_pty.c b/src/exec_pty.c
index c4954a812f765ff8632105368bf4af84d3656698..30922692b98382d54b769a955c33cf23b0a00fcd 100644 (file)
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -1157,9 +1157,14 @@ handle_sigchld(int backchannel, struct command_status *cstat)
     do {
        pid = waitpid(cmnd_pid, &status, WUNTRACED|WCONTINUED|WNOHANG);
     } while (pid == -1 && errno == EINTR);
-    if (pid <= 0) {
+    switch (pid) {
+    case 0:
+       errno = ECHILD;
+       /* FALLTHROUGH */
+    case -1:
        sudo_debug_printf(SUDO_DEBUG_DIAG,
            "waitpid returned %d, expected pid %d", pid, cmnd_pid);
+       sudo_warn(U_("%s: %s"), __func__, "waitpid");
        debug_return_bool(false);
     }
 
@@ -1168,18 +1173,22 @@ handle_sigchld(int backchannel, struct command_status *cstat)
     } else if (WIFSTOPPED(status)) {
        if (sig2str(WSTOPSIG(status), signame) == -1)
            snprintf(signame, sizeof(signame), "%d", WSTOPSIG(status));
-       sudo_debug_printf(SUDO_DEBUG_INFO, "command (%d) stopped, SIG%s",
-           cmnd_pid, signame);
+       sudo_debug_printf(SUDO_DEBUG_INFO, "%s: command (%d) stopped, SIG%s",
+           __func__, cmnd_pid, signame);
     } else if (WIFSIGNALED(status)) {
        if (sig2str(WTERMSIG(status), signame) == -1)
            snprintf(signame, sizeof(signame), "%d", WTERMSIG(status));
-       sudo_debug_printf(SUDO_DEBUG_INFO, "command (%d) killed, SIG%s",
-           cmnd_pid, signame);
+       sudo_debug_printf(SUDO_DEBUG_INFO, "%s: command (%d) killed, SIG%s",
+           __func__, cmnd_pid, signame);
        alive = false;
-    } else {
-       sudo_debug_printf(SUDO_DEBUG_INFO, "command (%d) exited: %d",
-           cmnd_pid, WEXITSTATUS(status));
+    } else if (WIFEXITED(status)) {
+       sudo_debug_printf(SUDO_DEBUG_INFO, "%s: command (%d) exited: %d",
+           __func__, cmnd_pid, WEXITSTATUS(status));
        alive = false;
+    } else {
+       sudo_debug_printf(SUDO_DEBUG_WARN,
+           "%s: unexpected wait status %d for command (%d)",
+           __func__, status, cmnd_pid);
     }
 
     /* Don't overwrite execve() failure with child exit status. */