From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754554Ab2CLG4U (ORCPT ); Mon, 12 Mar 2012 02:56:20 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:42317 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751269Ab2CLG4O (ORCPT ); Mon, 12 Mar 2012 02:56:14 -0400 From: Xiaotian Feng To: linux-kernel@vger.kernel.org Cc: Xiaotian Feng , Xiaotian Feng , Tejun Heo Subject: [PATCH] block: fix ioc leak in put_io_context Date: Mon, 12 Mar 2012 10:59:18 -0400 Message-Id: <1331564358-3058-1-git-send-email-xtfeng@gmail.com> X-Mailer: git-send-email 1.7.5.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When put_io_context is called, if ioc->icq_list is empty and refcount is 1, kernel will not free the ioc. This is caught by following kmemleak: unreferenced object 0xffff880036349fe0 (size 216): comm "sh", pid 2137, jiffies 4294931140 (age 290579.412s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 01 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... backtrace: [] kmemleak_alloc+0x26/0x50 [] kmem_cache_alloc_node+0x1cc/0x2a0 [] create_io_context_slowpath+0x27/0x130 [] get_task_io_context+0xbb/0xf0 [] copy_process+0x188e/0x18b0 [] do_fork+0x11b/0x420 [] sys_clone+0x28/0x30 [] stub_clone+0x13/0x20 [] 0xffffffffffffffff ioc->release_work() should be used even if ioc->icq_list is empty. Signed-off-by: Xiaotian Feng Cc: Tejun Heo Cc: Jens Axboe --- block/blk-ioc.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 8b782a6..d74a8ce 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -157,8 +157,7 @@ void put_io_context(struct io_context *ioc) */ if (atomic_long_dec_and_test(&ioc->refcount)) { spin_lock_irqsave(&ioc->lock, flags); - if (!hlist_empty(&ioc->icq_list)) - schedule_work(&ioc->release_work); + schedule_work(&ioc->release_work); spin_unlock_irqrestore(&ioc->lock, flags); } } -- 1.7.5.4