[SECURITY PATCH 06/28] iso9660: Don't leak memory on realloc() failures

[Daniel Kiper]

From: Peter Jones <pjones@redhat.com>

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/fs/iso9660.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/grub-core/fs/iso9660.c b/grub-core/fs/iso9660.c
index 7ba5b300b..5ec4433b8 100644
--- a/grub-core/fs/iso9660.c
+++ b/grub-core/fs/iso9660.c
@@ -533,14 +533,20 @@ add_part (struct iterate_dir_ctx *ctx,
 {
   int size = ctx->symlink ? grub_strlen (ctx->symlink) : 0;
   grub_size_t sz;
+  char *new;
 
   if (grub_add (size, len2, &sz) ||
       grub_add (sz, 1, &sz))
     return;
 
-  ctx->symlink = grub_realloc (ctx->symlink, sz);
-  if (! ctx->symlink)
-    return;
+  new = grub_realloc (ctx->symlink, sz);
+  if (!new)
+    {
+      grub_free (ctx->symlink);
+      ctx->symlink = NULL;
+      return;
+    }
+  ctx->symlink = new;
 
   grub_memcpy (ctx->symlink + size, part, len2);
   ctx->symlink[size + len2] = 0;  
@@ -634,7 +640,12 @@ susp_iterate_dir (struct grub_iso9660_susp_entry *entry,
                   is the length.  Both are part of the `Component
                   Record'.  */
                if (ctx->symlink && !ctx->was_continue)
-                 add_part (ctx, "/", 1);
+                 {
+                   add_part (ctx, "/", 1);
+                   if (grub_errno)
+                     return grub_errno;
+                 }
+
                add_part (ctx, (char *) &entry->data[pos + 2],
                          entry->data[pos + 1]);
                ctx->was_continue = (entry->data[pos] & 1);
@@ -653,6 +664,11 @@ susp_iterate_dir (struct grub_iso9660_susp_entry *entry,
              add_part (ctx, "/", 1);
              break;
            }
+
+         /* Check if grub_realloc() failed in add_part(). */
+         if (grub_errno)
+           return grub_errno;
+
          /* In pos + 1 the length of the `Component Record' is
             stored.  */
          pos += entry->data[pos + 1] + 2;
-- 
2.11.0