From: Gautam BT <gautambt@gmail.com>
Date: Mon, 9 Feb 2015 11:01:24 +0000 (+0530)
Subject: Fix pipe leak in exec plugin
X-Git-Tag: collectd-5.5.1~52^2~17
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=94e5622;p=collectd.git

Fix pipe leak in exec plugin

Fixes #762
---

diff --git a/src/exec.c b/src/exec.c
old mode 100644
new mode 100755
index 18124002..a9056334
--- a/src/exec.c
+++ b/src/exec.c
@@ -354,6 +354,33 @@ static void reset_signal_mask (void) /* {{{ */
   sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
 } /* }}} void reset_signal_mask */
 
+static void close_pipe(int fd_pipe[2])
+{
+  if(fd_pipe[0] != -1) {
+    close(fd_pipe[0]);
+  }
+
+  if(fd_pipe[1] != -1) {
+    close(fd_pipe[1]);
+  }
+}
+
+static int create_pipe(int fd_pipe[2])
+{
+  char errbuf[1024];
+  int status;
+
+  status = pipe (fd_pipe);
+  if (status != 0)
+  {
+    ERROR ("exec plugin: pipe failed: %s",
+        sstrerror (errno, errbuf, sizeof (errbuf)));
+    return (-1);
+  }
+
+  return 0;
+}
+
 /*
  * Creates three pipes (one for reading, one for writing and one for errors),
  * forks a child, sets up the pipes so that fd_in is connected to STDIN of
@@ -362,9 +389,9 @@ static void reset_signal_mask (void) /* {{{ */
  */
 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
 {
-  int fd_pipe_in[2];
-  int fd_pipe_out[2];
-  int fd_pipe_err[2];
+  int fd_pipe_in[2] = {-1, -1};
+  int fd_pipe_out[2] = {-1, -1};
+  int fd_pipe_err[2] = {-1, -1};
   char errbuf[1024];
   int status;
   int pid;
@@ -380,28 +407,8 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
   if (pl->pid != 0)
     return (-1);
 
-  status = pipe (fd_pipe_in);
-  if (status != 0)
-  {
-    ERROR ("exec plugin: pipe failed: %s",
-        sstrerror (errno, errbuf, sizeof (errbuf)));
-    return (-1);
-  }
-
-  status = pipe (fd_pipe_out);
-  if (status != 0)
-  {
-    ERROR ("exec plugin: pipe failed: %s",
-        sstrerror (errno, errbuf, sizeof (errbuf)));
-    return (-1);
-  }
-
-  status = pipe (fd_pipe_err);
-  if (status != 0)
-  {
-    ERROR ("exec plugin: pipe failed: %s",
-        sstrerror (errno, errbuf, sizeof (errbuf)));
-    return (-1);
+  if(create_pipe(fd_pipe_in) == -1 || create_pipe(fd_pipe_out) == -1 || create_pipe(fd_pipe_err) == -1) {
+    goto failed;
   }
 
   sp_ptr = NULL;
@@ -410,12 +417,13 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
   {
     ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
         pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
-    return (-1);
+    goto failed;
   }
+
   if (sp_ptr == NULL)
   {
     ERROR ("exec plugin: No such user: `%s'", pl->user);
-    return (-1);
+    goto failed;
   }
 
   uid = sp.pw_uid;
@@ -423,7 +431,7 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
   if (uid == 0)
   {
     ERROR ("exec plugin: Cowardly refusing to exec program as root.");
-    return (-1);
+    goto failed;
   }
 
   /* The group configured in the configfile is set as effective group, because
@@ -441,12 +449,12 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
         ERROR ("exec plugin: Failed to get group information "
             "for group ``%s'': %s", pl->group,
             sstrerror (errno, errbuf, sizeof (errbuf)));
-        return (-1);
+        goto failed;
       }
       if (NULL == gr_ptr)
       {
         ERROR ("exec plugin: No such group: `%s'", pl->group);
-        return (-1);
+        goto failed;
       }
 
       egid = gr.gr_gid;
@@ -462,7 +470,7 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
   {
     ERROR ("exec plugin: fork failed: %s",
         sstrerror (errno, errbuf, sizeof (errbuf)));
-    return (-1);
+    goto failed;
   }
   else if (pid == 0)
   {
@@ -530,6 +538,13 @@ static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err)
     close (fd_pipe_err[0]);
 
   return (pid);
+
+failed:
+  close_pipe(fd_pipe_in);
+  close_pipe(fd_pipe_out);
+  close_pipe(fd_pipe_err);
+
+  return (-1);
 } /* int fork_child }}} */
 
 static int parse_line (char *buffer) /* {{{ */