Merge pull request #137 from atalax/master

Fix two heap buffer overflows

2 files changed, 28 insertions, 4 deletions

diff --git a/libvncclient/rfbproto.c b/libvncclient/rfbproto.c
index 94b9bdb..9edfbad 100644
--- a/libvncclient/rfbproto.c
+++ b/libvncclient/rfbproto.c
@@ -147,6 +147,10 @@ void* rfbClientGetClientData(rfbClient* client, void* tag)
 
 /* messages */
 
+static boolean CheckRect(rfbClient* client, int x, int y, int w, int h) {
+  return x + w <= client->width && y + h <= client->height;
+}
+
 static void FillRectangle(rfbClient* client, int x, int y, int w, int h, uint32_t colour) {
   int i,j;
 
@@ -154,6 +158,11 @@ static void FillRectangle(rfbClient* client, int x, int y, int w, int h, uint32_
       return;
   }
 
+  if (!CheckRect(client, x, y, w, h)) {
+    rfbClientLog("Rect out of bounds: %dx%d at (%d, %d)\n", x, y, w, h);
+    return;
+  }
+
 #define FILL_RECT(BPP) \
     for(j=y*client->width;j<(y+h)*client->width;j+=client->width) \
       for(i=x;i<x+w;i++) \
@@ -175,6 +184,11 @@ static void CopyRectangle(rfbClient* client, uint8_t* buffer, int x, int y, int
       return;
   }
 
+  if (!CheckRect(client, x, y, w, h)) {
+    rfbClientLog("Rect out of bounds: %dx%d at (%d, %d)\n", x, y, w, h);
+    return;
+  }
+
 #define COPY_RECT(BPP) \
   { \
     int rs = w * BPP / 8, rs2 = client->width * BPP / 8; \
@@ -201,6 +215,16 @@ static void CopyRectangleFromRectangle(rfbClient* client, int src_x, int src_y,
       return;
   }
 
+  if (!CheckRect(client, src_x, src_y, w, h)) {
+    rfbClientLog("Source rect out of bounds: %dx%d at (%d, %d)\n", src_x, src_y, w, h);
+    return;
+  }
+
+  if (!CheckRect(client, dest_x, dest_y, w, h)) {
+    rfbClientLog("Dest rect out of bounds: %dx%d at (%d, %d)\n", dest_x, dest_y, w, h);
+    return;
+  }
+
 #define COPY_RECT_FROM_RECT(BPP) \
   { \
     uint##BPP##_t* _buffer=((uint##BPP##_t*)client->frameBuffer)+(src_y-dest_y)*client->width+src_x-dest_x; \
diff --git a/libvncclient/ultra.c b/libvncclient/ultra.c
index dac89b5..32a1b2b 100644
--- a/libvncclient/ultra.c
+++ b/libvncclient/ultra.c
@@ -86,14 +86,14 @@ HandleUltraBPP (rfbClient* client, int rx, int ry, int rw, int rh)
 
   /* uncompress the data */
   uncompressedBytes = client->raw_buffer_size;
-  inflateResult = lzo1x_decompress(
+  inflateResult = lzo1x_decompress_safe(
               (lzo_byte *)client->ultra_buffer, toRead,
               (lzo_byte *)client->raw_buffer, (lzo_uintp) &uncompressedBytes,
               NULL);
   
-  
+  /* Note that uncompressedBytes will be 0 on output overrun */
   if ((rw * rh * (BPP / 8)) != uncompressedBytes)
-      rfbClientLog("Ultra decompressed too little (%d < %d)", (rw * rh * (BPP / 8)), uncompressedBytes);
+      rfbClientLog("Ultra decompressed unexpected amount of data (%d != %d)\n", (rw * rh * (BPP / 8)), uncompressedBytes);
   
   /* Put the uncompressed contents of the update on the screen. */
   if ( inflateResult == LZO_E_OK ) 
@@ -168,7 +168,7 @@ HandleUltraZipBPP (rfbClient* client, int rx, int ry, int rw, int rh)
 
   /* uncompress the data */
   uncompressedBytes = client->raw_buffer_size;
-  inflateResult = lzo1x_decompress(
+  inflateResult = lzo1x_decompress_safe(
               (lzo_byte *)client->ultra_buffer, toRead,
               (lzo_byte *)client->raw_buffer, &uncompressedBytes, NULL);
   if ( inflateResult != LZO_E_OK )