From: Alfonso Gregory <83477269+AtariDreams@users.noreply.github.com>
Date: Sat, 28 Aug 2021 16:04:53 +0000 (-0400)
Subject: Fix undefined behavior regarding pData
X-Git-Tag: v2.4b1~83^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F228%2Fhead;p=thirdparty%2Fcups.git

Fix undefined behavior regarding pData

pData is a void pointer, and even though the address at request.pData[2] is being cast to that of a const UInt8 pointer, the request.pData has to be converted first BEFORE doing any pointer arithmetic. For this reason, it is best to write this it as a pointer sum, rather than an array.
---

diff --git a/backend/usb-darwin.c b/backend/usb-darwin.c
index 7c25905319..b17a9b382a 100644
--- a/backend/usb-darwin.c
+++ b/backend/usb-darwin.c
@@ -1616,14 +1616,14 @@ static CFStringRef copy_printer_interface_deviceid(printer_interface_t printer,
 
 			if (actualLength > 2 && actualLength <= bufferLength - 2)
 			{
-				ret = CFStringCreateWithBytes(NULL, (const UInt8 *) &request.pData[2], actualLength - 2, kCFStringEncodingUTF8, false);
+				ret = CFStringCreateWithBytes(NULL, (const UInt8 *)request.pData + 2, actualLength - 2, kCFStringEncodingUTF8, false);
 			}
 			else if (actualLength > 2) {
 				err = sendRequest(actualLength);
 				if (err == kIOReturnSuccess && request.wLenDone > 0)
 				{
 					actualLength = OSSwapBigToHostInt16(*((UInt16 *)request.pData));
-					ret = CFStringCreateWithBytes(NULL, (const UInt8 *) &request.pData[2], actualLength - 2, kCFStringEncodingUTF8, false);
+					ret = CFStringCreateWithBytes(NULL, (const UInt8 *)request.pData + 2, actualLength - 2, kCFStringEncodingUTF8, false);
 				}
 			}
 		}
@@ -1817,7 +1817,7 @@ static CFStringRef copy_printer_interface_indexed_description(printer_interface_
 	if ((description[0] & 1) != 0)
 		description[0] &= 0xfe;
 
-	char buffer[258] = {};
+	char buffer[258] = {0};
 	unsigned int maxLength = sizeof buffer;
 	if (description[0] > 1)
 	{