[PATCH v0] Fix double-free introduced by commit 33d02a42d64cf06cada1c389e5abba4b9d196cc5

[Jon McCune <jonmccune@google.com>]

To reproduce the problem, make sure you have a GPG public key available, build and install GRUB:
grub-install --debug --debug-image="all" --pubkey=/boot/pubkey.gpg --modules="serial terminfo gzio search search_label search_fs_uuid search_fs_file linux vbe video_fb video mmap relocator verify gcry_rsa gcry_dsa gcry_sha256 hashsum gcry_sha1 mpi echo loadenv boottime" /dev/sda
Sign all the files in /boot/grub/* and reboot.

I tested in a QEMU VM using an i386 target.  I was *not* able to successfully test the changes to the compression routines with 'make check'.  If somebody else could do that, it would be much appreciated.

Signed-off-by: Jon McCune <jonmccune@google.com>
---
 grub-core/commands/verify.c | 1 +
 grub-core/io/gzio.c         | 1 +
 grub-core/io/lzopio.c       | 1 +
 grub-core/io/xzio.c         | 1 +
 grub-core/kern/file.c       | 1 +
 5 files changed, 5 insertions(+)

diff --git a/grub-core/commands/verify.c b/grub-core/commands/verify.c
index dbe7e83..e14e07c 100644
--- a/grub-core/commands/verify.c
+++ b/grub-core/commands/verify.c
@@ -885,6 +885,7 @@ grub_pubkey_open (grub_file_t io, const char *filename)
   if (err)
     return NULL;
   io->device = 0;
+  io->name = 0;
   grub_file_close (io);
   return ret;
 }
diff --git a/grub-core/io/gzio.c b/grub-core/io/gzio.c
index 59ad6da..af222a8 100644
--- a/grub-core/io/gzio.c
+++ b/grub-core/io/gzio.c
@@ -1259,6 +1259,7 @@ grub_gzio_close (grub_file_t file)
 
   /* No need to close the same device twice.  */
   file->device = 0;
+  file->name = 0;
 
   return grub_errno;
 }
diff --git a/grub-core/io/lzopio.c b/grub-core/io/lzopio.c
index 2895e21..0606d41 100644
--- a/grub-core/io/lzopio.c
+++ b/grub-core/io/lzopio.c
@@ -525,6 +525,7 @@ grub_lzopio_close (grub_file_t file)
 
   /* Device must not be closed twice.  */
   file->device = 0;
+  file->name = 0;
   return grub_errno;
 }
 
diff --git a/grub-core/io/xzio.c b/grub-core/io/xzio.c
index bcce242..10eb595 100644
--- a/grub-core/io/xzio.c
+++ b/grub-core/io/xzio.c
@@ -319,6 +319,7 @@ grub_xzio_close (grub_file_t file)
 
   /* Device must not be closed twice.  */
   file->device = 0;
+  file->name = 0;
   return grub_errno;
 }
 
diff --git a/grub-core/kern/file.c b/grub-core/kern/file.c
index 24da12b..9083e4f 100644
--- a/grub-core/kern/file.c
+++ b/grub-core/kern/file.c
@@ -188,6 +188,7 @@ grub_file_close (grub_file_t file)
   if (file->device)
     grub_device_close (file->device);
   grub_free (file->name);
+  file->name = 0;
   grub_free (file);
   return grub_errno;
 }
-- 
1.8.5.1