Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967720Ab3HICJz (ORCPT ); Thu, 8 Aug 2013 22:09:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55803 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967679Ab3HIB7P (ORCPT ); Thu, 8 Aug 2013 21:59:15 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiang Liu , Minchan Kim Subject: [ 065/102] zram: protect sysfs handler from invalid memory access Date: Thu, 8 Aug 2013 18:57:41 -0700 Message-Id: <20130809015025.463998309@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130809015010.208118575@linuxfoundation.org> References: <20130809015010.208118575@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 46 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiang Liu 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 --- drivers/staging/zram/zram_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -188,8 +188,10 @@ static ssize_t mem_used_total_show(struc struct zram *zram = dev_to_zram(dev); struct zram_meta *meta = zram->meta; + down_read(&zram->init_lock); if (zram->init_done) val = zs_get_total_size_bytes(meta->mem_pool); + up_read(&zram->init_lock); return sprintf(buf, "%llu\n", val); } -- 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/