From patchwork Tue Jul 9 16:28:06 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 257756 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 684792C0099 for ; Wed, 10 Jul 2013 02:28:35 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UwamC-0006L9-JC; Tue, 09 Jul 2013 16:28:28 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Uwalr-0006Af-Jh for kernel-team@lists.ubuntu.com; Tue, 09 Jul 2013 16:28:07 +0000 Received: from bl15-104-132.dsl.telepac.pt ([188.80.104.132] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Uwalr-0007xF-CT; Tue, 09 Jul 2013 16:28:07 +0000 From: Luis Henriques To: Jiang Liu Subject: [ 3.8.y.z extended stable ] Patch "zram: protect sysfs handler from invalid memory access" has been added to staging queue Date: Tue, 9 Jul 2013 17:28:06 +0100 Message-Id: <1373387286-21023-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 X-Extended-Stable: 3.8 Cc: Minchan Kim , kernel-team@lists.ubuntu.com, Jiang Liu , Greg Kroah-Hartman X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled zram: protect sysfs handler from invalid memory access to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 13a9ce91021b81ead5e38106d960b6b31266e529 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Fri, 7 Jun 2013 00:07:27 +0800 Subject: [PATCH] zram: protect sysfs handler from invalid memory access commit 5863e10b441e7ea4b492f930f1be180a97d026f3 upstream. 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 Signed-off-by: Greg Kroah-Hartman [ luis: backported to 3.8: - protect access to zram->mem_pool instead of zram->meta ] Signed-off-by: Luis Henriques --- drivers/staging/zram/zram_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.8.1.2 diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index de1eacf..c07687e 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); }