Patch by Guillaume Morin

Fix two race conditions, as described at.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=212764


git-svn-id: svn://busybox.net/trunk/busybox@7567 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 13 insertions, 5 deletions

diff --git a/init/init.c b/init/init.c
index 85792c9b7..d332ccdbe 100644
--- a/init/init.c
+++ b/init/init.c
@@ -500,7 +500,12 @@ static pid_t run(const struct init_action *a)
                                 signal(SIGCHLD, SIG_DFL);
 
                                 /* Wait for child to exit */
-                                while ((tmp_pid = waitpid(pid, &junk, 0)) != pid);
+                                while ((tmp_pid = waitpid(pid, &junk, 0)) != pid) {
+                                        if (tmp_pid == -1 && errno == ECHILD) {
+                                                break;
+                                        }
+                                        /* FIXME handle other errors */
+                }
 
                                 /* See if stealing the controlling tty back is necessary */
                                 pgrp = tcgetpgrp(0);
@@ -624,12 +629,15 @@ static int waitfor(const struct init_action *a)
 
         pid = run(a);
         while (1) {
-                wpid = wait(&status);
-                if (wpid > 0 && wpid != pid) {
-                        continue;
-                }
+                wpid = waitpid(pid,&status,0);
                 if (wpid == pid)
                         break;
+                if (wpid == -1 && errno == ECHILD) {
+                        /* we missed its termination */
+                        break;
+                }
+                /* FIXME other errors should maybe trigger an error, but allow
+                 * the program to continue */
         }
         return wpid;
 }