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Put symlink at the end of the node and fix a potential

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memory corruption.

	* grub-core/fs/iso9660.c (grub_fshelp_node): New field have_symlink.
	Make symlink into an array.
	(set_rockridge): Set have_symlink and alloc_dirents.
	(grub_iso9660_read_symlink): Use new layout.
	(grub_iso9660_iterate_dir): Fix memory corruption.
	Use new layout.
	(grub_iso9660_dir): Set have_symlink.
	(grub_iso9660_open): Likewise.
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2011-11-10 09:31:06 +01:00
parent c3591189b8
commit f627652531
2 changed files with 58 additions and 11 deletions
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14
ChangeLog
View file

@ -1,3 +1,17 @@
2011-11-10 Vladimir Serbinenko <phcoder@gmail.com>
Put symlink at the end of the node and fix a potential
memory corruption.
* grub-core/fs/iso9660.c (grub_fshelp_node): New field have_symlink.
Make symlink into an array.
(set_rockridge): Set have_symlink and alloc_dirents.
(grub_iso9660_read_symlink): Use new layout.
(grub_iso9660_iterate_dir): Fix memory corruption.
Use new layout.
(grub_iso9660_dir): Set have_symlink.
(grub_iso9660_open): Likewise.
2011-11-10 Vladimir Serbinenko <phcoder@gmail.com>
Remove local keyword.

55
grub-core/fs/iso9660.c
View file

@ -159,8 +159,9 @@ struct grub_fshelp_node
{
struct grub_iso9660_data *data;
grub_size_t have_dirents, alloc_dirents;
char *symlink;
int have_symlink;
struct grub_iso9660_dir dirents[8];
char symlink[0];
};
enum
@ -408,9 +409,9 @@ set_rockridge (struct grub_iso9660_data *data)
struct grub_fshelp_node rootnode;
rootnode.data = data;
rootnode.alloc_dirents = 0;
rootnode.alloc_dirents = ARRAY_SIZE (rootnode.dirents);
rootnode.have_dirents = 1;
rootnode.symlink = 0;
rootnode.have_symlink = 0;
rootnode.dirents[0] = data->voldesc.rootdir;
/* The 2nd data byte stored how many bytes are skipped every time
@ -500,7 +501,10 @@ grub_iso9660_mount (grub_disk_t disk)
static char *
grub_iso9660_read_symlink (grub_fshelp_node_t node)
{
return node->symlink ? grub_strdup (node->symlink) : grub_strdup ("");
return node->have_symlink
? grub_strdup (node->symlink
+ (node->have_dirents) * sizeof (node->dirents[0])
- sizeof (node->dirents)) : grub_strdup ("");
}
static grub_off_t
@ -703,7 +707,7 @@ grub_iso9660_iterate_dir (grub_fshelp_node_t dir,
/* Setup a new node. */
node->data = dir->data;
node->symlink = symlink;
node->have_symlink = 0;
/* If the filetype was not stored using rockridge, use
whatever is stored in the iso9660 filesystem. */
@ -767,10 +771,11 @@ grub_iso9660_iterate_dir (grub_fshelp_node_t dir,
{
struct grub_fshelp_node *new_node;
node->alloc_dirents *= 2;
new_node = grub_malloc (sizeof (struct grub_fshelp_node)
+ ((node->alloc_dirents
- ARRAY_SIZE (node->dirents))
* sizeof (node->dirents[0])));
new_node = grub_realloc (node,
sizeof (struct grub_fshelp_node)
+ ((node->alloc_dirents
- ARRAY_SIZE (node->dirents))
* sizeof (node->dirents[0])));
if (!new_node)
{
if (filename_alloc)
@ -778,9 +783,37 @@ grub_iso9660_iterate_dir (grub_fshelp_node_t dir,
grub_free (node);
return 0;
}
node = new_node;
}
node->dirents[node->have_dirents++] = dirent;
}
if (symlink)
{
if ((node->alloc_dirents - node->have_dirents)
* sizeof (node->dirents[0]) < grub_strlen (symlink) + 1)
{
struct grub_fshelp_node *new_node;
new_node = grub_realloc (node,
sizeof (struct grub_fshelp_node)
+ ((node->alloc_dirents
- ARRAY_SIZE (node->dirents))
* sizeof (node->dirents[0]))
+ grub_strlen (symlink) + 1);
if (!new_node)
{
if (filename_alloc)
grub_free (filename);
grub_free (node);
return 0;
}
node = new_node;
}
node->have_symlink = 1;
grub_strcpy (node->symlink
+ node->have_dirents * sizeof (node->dirents[0])
- sizeof (node->dirents), symlink);
grub_free (symlink);
}
if (hook (filename, type, node))
{
if (filename_alloc)
@ -832,7 +865,7 @@ grub_iso9660_dir (grub_device_t device, const char *path,
rootnode.data = data;
rootnode.alloc_dirents = 0;
rootnode.have_dirents = 1;
rootnode.symlink = 0;
rootnode.have_symlink = 0;
rootnode.dirents[0] = data->voldesc.rootdir;
/* Use the fshelp function to traverse the path. */
@ -875,7 +908,7 @@ grub_iso9660_open (struct grub_file *file, const char *name)
rootnode.data = data;
rootnode.alloc_dirents = 0;
rootnode.have_dirents = 1;
rootnode.symlink = 0;
rootnode.have_symlink = 0;
rootnode.dirents[0] = data->voldesc.rootdir;
/* Use the fshelp function to traverse the path. */