From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Darren Kenny <darren.kenny@oracle.com>

Date: Thu, 26 Nov 2020 12:48:07 +0000

Subject: [PATCH] affs: Fix memory leaks

The node structure reference is being allocated but not freed if it

reaches the end of the function. If any of the hooks had returned

a non-zero value, then node would have been copied in to the context

reference, but otherwise node is not stored and should be freed.

Similarly, the call to grub_affs_create_node() replaces the allocated

memory in node with a newly allocated structure, leaking the existing

memory pointed by node.

Finally, when dir->parent is set, then we again replace node with newly

allocated memory, which seems unnecessary when we copy in the values

from dir->parent immediately after.

Fixes: CID 73759

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/fs/affs.c | 18 ++++++++----------

 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/grub-core/fs/affs.c b/grub-core/fs/affs.c

index 91073795f..e4615c743 100644

--- a/grub-core/fs/affs.c

+++ b/grub-core/fs/affs.c

@@ -400,12 +400,12 @@ grub_affs_iterate_dir (grub_fshelp_node_t dir,

 {

   unsigned int i;

   struct grub_affs_file file;

-  struct grub_fshelp_node *node = 0;

+  struct grub_fshelp_node *node, *orig_node;

   struct grub_affs_data *data = dir->data;

   grub_uint32_t *hashtable;

   /* Create the directory entries for `.' and `..'.  */

-  node = grub_zalloc (sizeof (*node));

+  node = orig_node = grub_zalloc (sizeof (*node));

   if (!node)

     return 1;

@@ -414,9 +414,6 @@ grub_affs_iterate_dir (grub_fshelp_node_t dir,

     return 1;

   if (dir->parent)

     {

-      node = grub_zalloc (sizeof (*node));

-      if (!node)

-	return 1;

       *node = *dir->parent;

       if (hook ("..", GRUB_FSHELP_DIR, node, hook_data))

 	return 1;

@@ -456,17 +453,18 @@ grub_affs_iterate_dir (grub_fshelp_node_t dir,

 	  if (grub_affs_create_node (dir, hook, hook_data, &node, &hashtable,

 				     next, &file))

-	    return 1;

+	    {

+	      /* Node has been replaced in function. */

+	      grub_free (orig_node);

+	      return 1;

+	    }

 	  next = grub_be_to_cpu32 (file.next);

 	}

     }

-  grub_free (hashtable);

-  return 0;

-

  fail:

-  grub_free (node);

+  grub_free (orig_node);

   grub_free (hashtable);

   return 0;

 }