[cpia] CPIA USB driver memory corruption

[Arjan van de Ven]

Hi,

The following patch fixs illegal memory accesses caused by the cpia driver
in 2.4.0-test1-ac7. The cause was that a kfree'd pointer wasn't set to
NULL so it was accessed as if it wasn't kfree'd.


Greetings,
  Arjan van de Ven

--- cpia_usb.c~	Fri Mar 31 04:00:01 2000
+++ cpia_usb.c	Fri Jun  2 19:08:53 2000
@@ -260,8 +260,10 @@
 
 error_all:
 	kfree (ucpia->sbuf[1].data);
+	ucpia->sbuf[1].data = NULL;
 error_0:
 	kfree (ucpia->sbuf[0].data);
+	ucpia->sbuf[0].data = NULL;
 	
 	return retval;
 }
@@ -436,8 +438,9 @@
 
 	cpia_usb_free_resources(ucpia, 1);
 
-	if (!ucpia->present)
+	if (!ucpia->present) 
 		kfree(ucpia);
+		
 
 	return 0;
 }
@@ -590,8 +593,10 @@
 		ucpia->buffers[0] = NULL;
 	}
 
-	if (!ucpia->open)
+	if (!ucpia->open) {
 		kfree(ucpia);
+		cam->lowlevel_data = NULL;
+	}
 }
 
 int usb_cpia_init(void)