--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -2273,6 +2273,10 @@
 	       bp->phy_addr = sdev->bus->sprom.et1phyaddr;
 	       break;
 	}
+	/* Some ROMs have buggy PHY addresses with the high
+	 * bits set (sign extension?). Truncate them to a
+	 * valid PHY address. */
+	bp->phy_addr &= 0x1F;
 
 	memcpy(bp->dev->dev_addr, addr, 6);
 
