- djm@cvs.openbsd.org 2010/12/15 00:49:27

     [readpass.c]
     fix ControlMaster=ask regression
     reset SIGCHLD handler before fork (and restore it after) so we don't miss
     the the askpass child's exit status. Correct test for exit status/signal to
     account for waitpid() failure; with claudio@ ok claudio@ markus@

1 files changed, 16 insertions, 11 deletions

diff --git a/readpass.c b/readpass.c
index bd144c2e3..599c8ef9a 100644
--- a/readpass.c
+++ b/readpass.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readpass.c,v 1.47 2006/08/03 03:34:42 deraadt Exp $ */
+/* $OpenBSD: readpass.c,v 1.48 2010/12/15 00:49:27 djm Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -33,6 +33,7 @@
 #ifdef HAVE_PATHS_H
 # include <paths.h>
 #endif
+#include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -49,11 +50,12 @@
 static char *
 ssh_askpass(char *askpass, const char *msg)
 {
-        pid_t pid;
+        pid_t pid, ret;
         size_t len;
         char *pass;
-        int p[2], status, ret;
+        int p[2], status;
         char buf[1024];
+        void (*osigchld)(int);
 
         if (fflush(stdout) != 0)
                 error("ssh_askpass: fflush: %s", strerror(errno));
@@ -63,8 +65,10 @@ ssh_askpass(char *askpass, const char *msg)
                 error("ssh_askpass: pipe: %s", strerror(errno));
                 return NULL;
         }
+        osigchld = signal(SIGCHLD, SIG_DFL);
         if ((pid = fork()) < 0) {
                 error("ssh_askpass: fork: %s", strerror(errno));
+                signal(SIGCHLD, osigchld);
                 return NULL;
         }
         if (pid == 0) {
@@ -77,23 +81,24 @@ ssh_askpass(char *askpass, const char *msg)
         }
         close(p[1]);
 
-        len = ret = 0;
+        len = 0;
         do {
-                ret = read(p[0], buf + len, sizeof(buf) - 1 - len);
-                if (ret == -1 && errno == EINTR)
+                ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
+
+                if (r == -1 && errno == EINTR)
                         continue;
-                if (ret <= 0)
+                if (r <= 0)
                         break;
-                len += ret;
+                len += r;
         } while (sizeof(buf) - 1 - len > 0);
         buf[len] = '\0';
 
         close(p[0]);
-        while (waitpid(pid, &status, 0) < 0)
+        while ((ret = waitpid(pid, &status, 0)) < 0)
                 if (errno != EINTR)
                         break;
-
-        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        signal(SIGCHLD, osigchld);
+        if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
                 memset(buf, 0, sizeof(buf));
                 return NULL;
         }