From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757334Ab3IKFgk (ORCPT ); Wed, 11 Sep 2013 01:36:40 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:5606 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670Ab3IKE5S (ORCPT ); Wed, 11 Sep 2013 00:57:18 -0400 X-Authority-Analysis: v=2.0 cv=V4T/IJbi c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=7LSKei67pZYA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=dgW8Ds1fvp0A:10 a=pGLkceISAAAA:8 a=i0EeH86SAAAA:8 a=VwQbUJbxAAAA:8 a=ag1SF4gXAAAA:8 a=5cIBTxRJ4pZzZk2xk6UA:9 a=MSl-tDqOz04A:10 a=hPjdaMEvmhQA:10 a=LI9Vle30uBYA:10 a=1TSTQ8KKaH4A:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130911042917.296227051@goodmis.org> User-Agent: quilt/0.60-1 Date: Wed, 11 Sep 2013 00:29:37 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jiang Liu , Minchan Kim , Greg Kroah-Hartman Subject: [150/251] zram: protect sysfs handler from invalid memory access References: <20130911042707.738353451@goodmis.org> Content-Disposition: inline; filename=0150-zram-protect-sysfs-handler-from-invalid-memory-acces.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.9-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiang Liu [ Upstream commit 5863e10b441e7ea4b492f930f1be180a97d026f3 ] Use zram->init_lock to protect access to zram->meta, otherwise it may cause invalid memory access if zram->meta has been freed by zram_reset_device(). This issue may be triggered by: Thread 1: while true; do cat mem_used_total; done Thread 2: while true; do echo 8M > disksize; echo 1 > reset; done Signed-off-by: Jiang Liu Acked-by: Minchan Kim Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Steven Rostedt --- drivers/staging/zram/zram_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index edb0ed4..5e07628 100644 --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -186,8 +186,10 @@ static ssize_t mem_used_total_show(struct device *dev, u64 val = 0; struct zram *zram = dev_to_zram(dev); + down_read(&zram->init_lock); if (zram->init_done) val = zs_get_total_size_bytes(zram->mem_pool); + up_read(&zram->init_lock); return sprintf(buf, "%llu\n", val); } -- 1.7.10.4