fix(fdt): fix OOB write in uuid parsing function
The function read_uuid() zeroes the UUID destination buffer
on error. However, it mistakenly uses the dest pointer
that has been incremented many times during the parsing,
leading to an out-of-bounds write.
To fix this, retain a pointer to the start of the buffer,
and use this when clearing it instead.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
Change-Id: Iee8857be5d3f383ca2eab86cde99a43bf606f306
diff --git a/common/uuid.c b/common/uuid.c
index dd3c7b0..ac6db50 100644
--- a/common/uuid.c
+++ b/common/uuid.c
@@ -73,6 +73,7 @@
int read_uuid(uint8_t *dest, char *uuid)
{
int err;
+ uint8_t *dest_start = dest;
/* Check that we have enough characters */
if (strnlen(uuid, UUID_STRING_LENGTH) != UUID_STRING_LENGTH) {
@@ -124,7 +125,7 @@
if (err < 0) {
WARN("Error parsing UUID\n");
/* Clear the buffer on error */
- memset((void *)dest, '\0', UUID_BYTES_LENGTH * sizeof(uint8_t));
+ memset((void *)dest_start, '\0', UUID_BYTES_LENGTH * sizeof(uint8_t));
return -EINVAL;
}