Re: [Libguestfs] [PATCH 2/7] lib: Use vk->len for string conversion
On Sat, Jan 11, 2014 at 12:12:47AM +0100, Hilko Bengen wrote:
---
lib/value.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/lib/value.c b/lib/value.c
index 65404d7..e700c84 100644
--- a/lib/value.c
+++ b/lib/value.c
@@ -207,14 +207,8 @@ hivex_value_key (hive_h *h, hive_value_h value)
struct ntreg_vk_record *vk =
(struct ntreg_vk_record *) ((char *) h->addr + value);
- /* AFAIK the key is always plain ASCII, so no conversion to UTF-8 is
- * necessary. However we do need to nul-terminate the string.
- */
- errno = 0;
- size_t len = hivex_value_key_len (h, value);
- if (len == 0 && errno != 0)
- return NULL;
size_t flags = le16toh (vk->flags);
+ size_t len = le16toh (vk->name_len);
I think this effectively removes a check. hivex_value_key_len
contains this code:
size_t seg_len = block_len (h, value, NULL);
if (sizeof (struct ntreg_vk_record) + len - 1 > seg_len) {
SET_ERRNO (EFAULT, "key length is too long (%zu, %zu)", len, seg_len);
return 0;
}
but after this change, this would no longer be run, so it would be
possible to overrun the registry, or at least overrun the end of a
block.
Is there a reason for this patch? It seems like just an optimization.
Rich.
--
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