xnu-3789.51.2.tar.gz

[apple/xnu.git] / iokit / Kernel / IOBufferMemoryDescriptor.cpp

diff --git a/iokit/Kernel/IOBufferMemoryDescriptor.cpp b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
index 046274c5945f768b2e6a3e6baff6ed77714b12fc..5641d3b9ea42c5329b78d58708cda1a8daf36ebd 100644 (file)
--- a/iokit/Kernel/IOBufferMemoryDescriptor.cpp
+++ b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
@@ -626,6 +626,9 @@ void *
 IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
 {
     IOVirtualAddress address;
+
+    if ((start + withLength) < start) return 0;
+
     if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask))
        address = (IOVirtualAddress) _buffer;
     else