Re: [cp-patches] Patch: avoid buffer overflow in socket read

[Anthony Green]

On Mon, 2005-12-26 at 18:58 -0700, Tom Tromey wrote:
> >>>>> "Anthony" == Anthony Green <address@hidden> writes:
> 
> Anthony> This next patch computes right amount of data to read from a
> Anthony> socket to stuff in a Buffer.  When dst.limit < dst.capacity,
> Anthony> we're trying to put too much data into the buffer and we get
> Anthony> a buffer overflow exception.
> 
> Anthony> Ok to apply?
> 
> Yes, thanks.  Could you look at the similar code in
> DatagramChannelImpl.java and, if needed, apply the same fix there?

Good thinking.  Here's the final patch that I applied..


2005-12-26  Anthony Green  <address@hidden>

        * gnu/java/nio/SocketChannelImpl.java (read): Compute the right amount 
        of data to read (dst.remaining()).
        * gnu/java/nio/DatagramChannelImpl.java (receive): Ditto.


--- gnu/java/nio/SocketChannelImpl.java.~1.28.~ 2005-11-11 04:04:03.000000000 
-0800
+++ gnu/java/nio/SocketChannelImpl.java 2005-12-26 17:34:14.000000000 -0800
@@ -220,7 +220,7 @@
     int offset = 0;
     InputStream input = socket.getInputStream();
     int available = input.available();
-    int len = dst.capacity() - dst.position();
+    int len = dst.remaining();
        
     if ((! isBlocking()) && available == 0)
       return 0;
--- gnu/java/nio/DatagramChannelImpl.java.~1.14.~       2005-07-02 
13:32:13.000000000 -0700
+++ gnu/java/nio/DatagramChannelImpl.java       2005-12-26 18:21:47.000000000 
-0800
@@ -201,7 +201,7 @@
     try
       {
         DatagramPacket packet;
-        int len = dst.capacity() - dst.position();
+        int len = dst.remaining();
         
         if (dst.hasArray())
           {