xnu-3789.21.4.tar.gz

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

diff --git a/iokit/Kernel/IOBufferMemoryDescriptor.cpp b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
index 9f190260568723c5ebda960eb7401c2a3521c0e8..5641d3b9ea42c5329b78d58708cda1a8daf36ebd 100644 (file)
--- a/iokit/Kernel/IOBufferMemoryDescriptor.cpp
+++ b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
@@ -554,6 +554,7 @@ vm_size_t IOBufferMemoryDescriptor::getCapacity() const
 void IOBufferMemoryDescriptor::setLength(vm_size_t length)
 {
     assert(length <= _capacity);
+    if (length > _capacity) return;
 
     _length = length;
     _ranges.v64->length = length;
@@ -625,6 +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