opl3_oss use after free.

[Dave Jones <davej@redhat.com>]

Don't read from free'd memory.  Also make use of the return
value, and don't register the device if something went wrong
creating the port.

Coverity #955

Signed-off-by: Dave Jones <davej@redhat.com>

--- linux-2.6/sound/drivers/opl3/opl3_oss.c~	2006-03-06 03:59:35.000000000 -0500
+++ linux-2.6/sound/drivers/opl3/opl3_oss.c	2006-03-06 04:03:44.000000000 -0500
@@ -104,8 +104,10 @@ static int snd_opl3_oss_create_port(stru
 							  voices, voices,
 							  name);
 	if (opl3->oss_chset->port < 0) {
+		int port;
+		port = opl3->oss_chset->port;
 		snd_midi_channel_free_set(opl3->oss_chset);
-		return opl3->oss_chset->port;
+		return port;
 	}
 	return 0;
 }
@@ -136,10 +138,10 @@ void snd_opl3_init_seq_oss(struct snd_op
 	arg->oper = oss_callback;
 	arg->private_data = opl3;
 
-	snd_opl3_oss_create_port(opl3);
-
-	/* register to OSS synth table */
-	snd_device_register(opl3->card, dev);
+	if (snd_opl3_oss_create_port(opl3)) {
+		/* register to OSS synth table */
+		snd_device_register(opl3->card, dev);
+	}
 }
 
 /* unregister */

-- 
http://www.codemonkey.org.uk