[PATCH 4/8] usb: sandbox: Check for string end in copy_to_unicode()

Andrew Scull
2022-04-03T10:40:34Z

When copying the string in copy_to_unicode(), check for the null
terminator in each position, not just at the start, to avoid reading
beyond the end of the string.

Signed-off-by: Andrew Scull <ascull@google.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Marek Vasut <marex@denx.de>
---
drivers/usb/emul/usb-emul-uclass.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/emul/usb-emul-uclass.c b/drivers/usb/emul/usb-emul-uclass.c
index 05f6d3d9e2..b31dc950e3 100644
--- a/drivers/usb/emul/usb-emul-uclass.c
+++ b/drivers/usb/emul/usb-emul-uclass.c
@@ -15,13 +15,12 @@
static int copy_to_unicode(char *buff, int length, const char *str)
{
int ptr;
- int i;

if (length < 2)
return 0;
buff[1] = USB_DT_STRING;
- for (ptr = 2, i = 0; ptr + 1 < length && *str; i++, ptr += 2) {
- buff[ptr] = str[i];
+ for (ptr = 2; ptr + 1 < length && *str; str++, ptr += 2) {
+ buff[ptr] = *str;
buff[ptr + 1] = 0;
}
buff[0] = ptr;
--
2.35.1.1094.g7c7d902a7c-goog