commit a03058723a03080456814d5212c3caceacc58ae9
author Craig Hutchinson <54269136+CraigHutchinson@users.noreply.github.com> Tue Jun 08 20:03:43 2021 +0200
committer Nathan Hjelm <hjelmn@google.com> Thu Jul 08 21:52:14 2021 -0600
tree 4cb34f8bcc09d24af9945af7eb7ad21b64d57798
parent 68289d0d038b42e177d50fec9e26b8175d302627

windows: Allow GUID with and without trailing zeroes

Improve the GUID length check to accommodate the cases where the GUID
string fetched from registry does not have a trailing zero, or if a
multi-string entry, one or two trailing zeroes.

Closes #927

Signed-off-by: Craig Hutchinson <54269136+CraigHutchinson@users.noreply.github.com>
[Tormod: Use correct types and simplify comparisons]
Signed-off-by: Tormod Volden <debian.tormod@gmail.com>
Signed-off-by: Nathan Hjelm <hjelmn@google.com>

libusb/os/windows_winusb.c

diff --git a/libusb/os/windows_winusb.c b/libusb/os/windows_winusb.c
index cdca6cb..1fdc703 100644
--- a/libusb/os/windows_winusb.c
+++ b/libusb/os/windows_winusb.c
@@ -1626,9 +1626,15 @@
 					s = pRegQueryValueExA(key, "DeviceInterfaceGUID", NULL, &reg_type,
 						(LPBYTE)guid_string, &size);
 				pRegCloseKey(key);
-				if ((s == ERROR_SUCCESS) &&
-				    (((reg_type == REG_SZ) && (size == (sizeof(guid_string) - sizeof(char)))) ||
-				     ((reg_type == REG_MULTI_SZ) && (size == sizeof(guid_string))))) {
+				if (s != ERROR_SUCCESS) {
+					usbi_warn(ctx, "unexpected error from pRegQueryValueExA for '%s'", dev_id);
+					break;
+				}
+				// https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regqueryvalueexa#remarks
+				// - "string may not have been stored with the proper terminating null characters"
+				// - "Note that REG_MULTI_SZ strings could have two terminating null characters"
+			        if ((reg_type == REG_SZ && size >= sizeof(guid_string) - sizeof(char))
+				    || (reg_type == REG_MULTI_SZ && size >= sizeof(guid_string) - 2 * sizeof(char))) {
 					if (nb_guids == guid_size) {
 						new_guid_list = realloc((void *)guid_list, (guid_size + GUID_SIZE_STEP) * sizeof(void *));
 						if (new_guid_list == NULL) {
@@ -1660,7 +1666,7 @@
 							free(if_guid);
 						}
 					}
-				} else if (s == ERROR_SUCCESS) {
+				} else {
 					usbi_warn(ctx, "unexpected type/size of DeviceInterfaceGUID for '%s'", dev_id);
 				}
 				break;

libusb/version_nano.h

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 20dc30c..b2f7e4a 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11631
+#define LIBUSB_NANO 11632