X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/b36670cedae0009469e8ee117453de831de64a6b..0c530ab8987f0ae6a1a3d9284f40182b88852816:/osfmk/ipc/ipc_kmsg.c

diff --git a/osfmk/ipc/ipc_kmsg.c b/osfmk/ipc/ipc_kmsg.c
index 5fde45534..9f524e034 100644
--- a/osfmk/ipc/ipc_kmsg.c
+++ b/osfmk/ipc/ipc_kmsg.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -200,8 +200,6 @@ ipc_kmsg_alloc(
 	ipc_kmsg_t kmsg;
 
 #if !defined(__LP64__)
-	mach_msg_size_t size = msg_and_trailer_size - MAX_TRAILER_SIZE;
-
 	/*
 	 * LP64support -
 	 * Pad the allocation in case we need to expand the
@@ -215,20 +213,23 @@ ipc_kmsg_alloc(
 	 * forward as we process them than it is to push all the
 	 * data backwards.
 	 */
-	max_expanded_size = 
-		(size > sizeof(mach_msg_base_t)) ?
-		(msg_and_trailer_size + DESC_SIZE_ADJUSTMENT * 
-		 ((size - sizeof(mach_msg_base_t)) /
-		  (sizeof(mach_msg_ool_descriptor_t))))
-		:
-		(msg_and_trailer_size);
-#else
-	max_expanded_size = msg_and_trailer_size;
+
+	mach_msg_size_t size = msg_and_trailer_size - MAX_TRAILER_SIZE;
+	if (size > sizeof(mach_msg_base_t)) {
+		mach_msg_size_t max_desc = ((size - sizeof(mach_msg_base_t)) /
+				           sizeof(mach_msg_ool_descriptor_t)) *
+				           DESC_SIZE_ADJUSTMENT;
+		if (msg_and_trailer_size >= MACH_MSG_SIZE_MAX - max_desc)
+			return IKM_NULL;
+		max_expanded_size = msg_and_trailer_size + max_desc;
+	} else
 #endif
+		max_expanded_size = msg_and_trailer_size;
 
-	/* round up for ikm_cache */
-	if (max_expanded_size < IKM_SAVED_MSG_SIZE)
-		max_expanded_size = IKM_SAVED_MSG_SIZE;
+	if (max_expanded_size > ikm_less_overhead(MACH_MSG_SIZE_MAX))
+		return IKM_NULL;
+	else if (max_expanded_size < IKM_SAVED_MSG_SIZE)
+		max_expanded_size = IKM_SAVED_MSG_SIZE; 	/* round up for ikm_cache */
 
 	if (max_expanded_size == IKM_SAVED_MSG_SIZE) {
 		struct ikm_cache	*cache;
@@ -712,6 +713,9 @@ ipc_kmsg_get(
 	if ((size < sizeof(mach_msg_header_t)) || (size & 3))
 		return MACH_SEND_MSG_TOO_SMALL;
 
+	if (size > MACH_MSG_SIZE_MAX - MAX_TRAILER_SIZE)
+		return MACH_SEND_TOO_LARGE;
+
 	msg_and_trailer_size = size + MAX_TRAILER_SIZE;
 
 	kmsg = ipc_kmsg_alloc(msg_and_trailer_size);
@@ -775,7 +779,7 @@ ipc_kmsg_get_from_kernel(
 	ipc_port_t	dest_port;
 
 	assert(size >= sizeof(mach_msg_header_t));
-	assert((size & 3) == 0);
+//	assert((size & 3) == 0);
 
 	assert(IP_VALID((ipc_port_t) msg->msgh_remote_port));
 	dest_port = (ipc_port_t)msg->msgh_remote_port;