From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758046Ab3HMQ1f (ORCPT ); Tue, 13 Aug 2013 12:27:35 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:33381 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758136Ab3HMQ1A (ORCPT ); Tue, 13 Aug 2013 12:27:00 -0400 X-Authority-Analysis: v=2.0 cv=P6i4d18u c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=0AC-v-DXK1QA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=OpnfZr6NaHgA:10 a=pGLkceISAAAA:8 a=yPCof4ZbAAAA:8 a=Z4Rwk6OoAAAA:8 a=5cIBTxRJ4pZzZk2xk6UA:9 a=MSl-tDqOz04A:10 a=7DSvI1NPTFQA:10 a=jbrJJM5MRmoA:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130813155832.166886525@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 13 Aug 2013 11:57:48 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dan Carpenter , Jens Axboe , Andrew Morton Subject: [54/88] drivers/cdrom/cdrom.c: use kzalloc() for failing hardware References: <20130813155654.069291373@goodmis.org> Content-Disposition: inline; filename=0054-drivers-cdrom-cdrom.c-use-kzalloc-for-failing-hardwa.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.7-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Jonathan Salwan [ Upstream commit 542db01579fbb7ea7d1f7bb9ddcef1559df660b2 ] In drivers/cdrom/cdrom.c mmc_ioctl_cdrom_read_data() allocates a memory area with kmalloc in line 2885. 2885 cgc->buffer = kmalloc(blocksize, GFP_KERNEL); 2886 if (cgc->buffer == NULL) 2887 return -ENOMEM; In line 2908 we can find the copy_to_user function: 2908 if (!ret && copy_to_user(arg, cgc->buffer, blocksize)) The cgc->buffer is never cleaned and initialized before this function. If ret = 0 with the previous basic block, it's possible to display some memory bytes in kernel space from userspace. When we read a block from the disk it normally fills the ->buffer but if the drive is malfunctioning there is a chance that it would only be partially filled. The result is an leak information to userspace. Signed-off-by: Dan Carpenter Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Steven Rostedt --- drivers/cdrom/cdrom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index d620b44..8a3aff7 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -2882,7 +2882,7 @@ static noinline int mmc_ioctl_cdrom_read_data(struct cdrom_device_info *cdi, if (lba < 0) return -EINVAL; - cgc->buffer = kmalloc(blocksize, GFP_KERNEL); + cgc->buffer = kzalloc(blocksize, GFP_KERNEL); if (cgc->buffer == NULL) return -ENOMEM; -- 1.7.10.4