X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..e3027f41d0120b4278cca462f397b6619dcd9ac5:/iokit/Families/IOStorage/IOBlockStorageDriver.cpp?ds=sidebyside

diff --git a/iokit/Families/IOStorage/IOBlockStorageDriver.cpp b/iokit/Families/IOStorage/IOBlockStorageDriver.cpp
index 8e843b49a..345e55b56 100644
--- a/iokit/Families/IOStorage/IOBlockStorageDriver.cpp
+++ b/iokit/Families/IOStorage/IOBlockStorageDriver.cpp
@@ -1759,7 +1759,7 @@ IOByteCount IODeblocker::readBytes( IOByteCount offset,
 
     for ( ; index < _chunksCount && withLength; index++)
     {
-        IOByteCount copy   = min(_chunks[index].length, withLength);
+        IOByteCount copy   = min(_chunks[index].length - offset, withLength);
         IOByteCount copied = _chunks[index].buffer->readBytes(
                                     /* offset */ offset + _chunks[index].offset,
                                     /* bytes  */ bytes,
@@ -1798,7 +1798,7 @@ IOByteCount IODeblocker::writeBytes( IOByteCount  offset,
 
     for ( ; index < _chunksCount && withLength; index++)
     {
-        IOByteCount copy   = min(_chunks[index].length, withLength);
+        IOByteCount copy   = min(_chunks[index].length - offset, withLength);
         IOByteCount copied = _chunks[index].buffer->writeBytes(
                                     /* offset */ offset + _chunks[index].offset,
                                     /* bytes  */ bytes,