[binutils-gdb] Close resource leaks in the BFD library's plugin handler.

[Nick Clifton]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=103da91bc083f94769e3758175a96d06cef1f8fe

commit 103da91bc083f94769e3758175a96d06cef1f8fe
Author: Nick Clifton <nickc@redhat.com>
Date:   Wed Aug 1 14:34:41 2018 +0100

    Close resource leaks in the BFD library's plugin handler.
    
    	PR 23460
    	* plugin.c (bfd_plugin_open_input): Close file descriptor if the
    	call to fstat fails.
    	(try_claim): Always close the file descriptor at the end of the
    	function.
    	(try_load_plugin): If a plugin has already been registered, then
    	skip the dlopen and onload steps and go straight to claiming the
    	file.  If these is an error, close the plugin.

Diff:
---
 bfd/ChangeLog | 11 +++++++++++
 bfd/plugin.c  | 26 +++++++++++++++++++-------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index aebedba..117a8db 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,14 @@
+2018-08-01  Zenith  <zenith432@users.sourceforge.net>
+
+	PR 23460
+	* plugin.c (bfd_plugin_open_input): Close file descriptor if the
+	call to fstat fails.
+	(try_claim): Always close the file descriptor at the end of the
+	function.
+	(try_load_plugin): If a plugin has already been registered, then
+	skip the dlopen and onload steps and go straight to claiming the
+	file.  If these is an error, close the plugin.
+
 2018-08-01  Alan Modra  <amodra@gmail.com>
 
 	* elf64-ppc.c (plt_stub_pad): Delay plt_stub_size call until needed.
diff --git a/bfd/plugin.c b/bfd/plugin.c
index 7c5bba2..d9b9e2f 100644
--- a/bfd/plugin.c
+++ b/bfd/plugin.c
@@ -124,7 +124,7 @@ message (int level ATTRIBUTE_UNUSED,
 }
 
 /* Register a claim-file handler. */
-static ld_plugin_claim_file_handler claim_file;
+static ld_plugin_claim_file_handler claim_file = NULL;
 
 static enum ld_plugin_status
 register_claim_file (ld_plugin_claim_file_handler handler)
@@ -186,8 +186,13 @@ bfd_plugin_open_input (bfd *ibfd, struct ld_plugin_input_file *file)
   if (iobfd == ibfd)
     {
       struct stat stat_buf;
+
       if (fstat (file->fd, &stat_buf))
-	return 0;
+	{
+	  close(file->fd);
+	  return 0;
+	}
+
       file->offset = 0;
       file->filesize = stat_buf.st_size;
     }
@@ -208,21 +213,24 @@ try_claim (bfd *abfd)
   file.handle = abfd;
   if (!bfd_plugin_open_input (abfd, &file))
     return 0;
-  claim_file (&file, &claimed);
-  if (!claimed)
-    close (file.fd);
+  if (claim_file)
+    claim_file (&file, &claimed);
+  close (file.fd);
   return claimed;
 }
 
 static int
 try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
 {
-  void *plugin_handle;
+  void *plugin_handle = NULL;
   struct ld_plugin_tv tv[4];
   int i;
   ld_plugin_onload onload;
   enum ld_plugin_status status;
 
+  if (claim_file)
+    goto have_claim_file;
+
   *has_plugin_p = 0;
 
   plugin_handle = dlopen (pname, RTLD_NOW);
@@ -257,6 +265,7 @@ try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
   if (status != LDPS_OK)
     goto err;
 
+have_claim_file:
   *has_plugin_p = 1;
 
   abfd->plugin_format = bfd_plugin_no;
@@ -272,6 +281,9 @@ try_load_plugin (const char *pname, bfd *abfd, int *has_plugin_p)
   return 1;
 
  err:
+  if (plugin_handle)
+    dlclose (plugin_handle);
+  register_claim_file (NULL);
   return 0;
 }
 
@@ -362,7 +374,7 @@ load_plugin (bfd *abfd)
       int valid_plugin;
 
       full_name = concat (p, "/", ent->d_name, NULL);
-      if (stat(full_name, &s) == 0 && S_ISREG (s.st_mode))
+      if (stat (full_name, &s) == 0 && S_ISREG (s.st_mode))
 	found = try_load_plugin (full_name, abfd, &valid_plugin);
       if (has_plugin <= 0)
 	has_plugin = valid_plugin;