diff  -u linux-2.4.x/arch/um/drivers/chan_kern.c
--- linux-2.4.x/arch/um/drivers/chan_kern.c.orig
+++ linux-2.4.x/arch/um/drivers/chan_kern.c	2003-12-03 10:49:11.000000000 +1000
@@ -175,13 +175,21 @@
 	 * state.  Then, the first one opened will have the original state,
 	 * so it must be the last closed.
 	 */
-        for(ele = chans->prev; ele != chans; ele = ele->prev){
-                chan = list_entry(ele, struct chan, list);
-		if(!chan->opened) continue;
-		if(chan->ops->close != NULL)
-			(*chan->ops->close)(chan->fd, chan->data);
+	for(ele = chans->prev; ele != chans; ele = prev){
+		/* Note that the close function can trigger a signal
+		 * which will close this channel from under us, so
+		 * we need to do everything for the channel
+		 * before we call close */
+		int fd;
+		prev = ele->prev;
+
+		chan = list_entry(ele, struct chan, list);
+		if (!chan->opened) continue;
+		fd = chan->fd;
 		chan->opened = 0;
 		chan->fd = -1;
+		if(chan->ops->close != NULL)
+			(*chan->ops->close)(fd, chan->data);
 	}
 }