Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933382Ab1CXHaW (ORCPT ); Thu, 24 Mar 2011 03:30:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9537 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933306Ab1CXHaU (ORCPT ); Thu, 24 Mar 2011 03:30:20 -0400 From: Amit Shah To: linuxppc-dev@ozlabs.org Cc: Rusty Russell , linux-kernel@vger.kernel.org, benh@kernel.crashing.org, greg@kroah.com, Amit Shah , stable@kernel.org Subject: [PATCH] hvc_console: Don't access hvc_task if not initialised Date: Thu, 24 Mar 2011 12:59:58 +0530 Message-Id: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1121 Lines: 36 hvc_open() can be called without having any backing device. This results in a call to hvc_kick() which calls wake_up_process on a NULL pointer. Ensure hvc is initialised by checking for a non-NULL hvc_task before waking up the hvc thread. This was found by an autotest run for virtio_console without having a console backend. CC: stable@kernel.org Signed-off-by: Amit Shah --- drivers/tty/hvc/hvc_console.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index e9cba13..b2cb5cc 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -286,6 +286,9 @@ EXPORT_SYMBOL_GPL(hvc_instantiate); /* Wake the sleeping khvcd */ void hvc_kick(void) { + if (!hvc_task) + return; + hvc_kicked = 1; wake_up_process(hvc_task); } -- 1.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/