Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   <alex.bou9@gmail.com>
To:     "'Dan Carpenter'" <dan.carpenter@oracle.com>,
        "'Andrew Morton'" <akpm@linux-foundation.org>
Cc:     "'Ira Weiny'" <ira.weiny@intel.com>,
        <linux-kernel@vger.kernel.org>, <kernel-janitors@vger.kernel.org>,
        "'Matt Porter'" <mporter@kernel.crashing.org>
References: <20190529110601.GB19119@mwanda>
In-Reply-To: <20190529110601.GB19119@mwanda>
Subject: RE: [PATCH] rapidio/mport_cdev: NUL terminate some strings
Date:   Thu, 20 Jun 2019 21:08:43 -0400
Message-ID: <001101d527cd$e03b0180$a0b10480$@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain;
        charset="us-ascii"
Content-Transfer-Encoding: 7bit
Thread-Index: AQHqSTig6vd4VCxw0340JcsQqG4IG6Z7CPbw
Content-Language: en-us
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Acked-by: Alexandre Bounine <alex.bou9@gmail.com>  

-----Original Message-----
From: Dan Carpenter <dan.carpenter@oracle.com> 
Sent: Wednesday, May 29, 2019 7:06 AM
To: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>; Andrew Morton
<akpm@linux-foundation.org>; Ira Weiny <ira.weiny@intel.com>;
linux-kernel@vger.kernel.org; kernel-janitors@vger.kernel.org
Subject: [PATCH] rapidio/mport_cdev: NUL terminate some strings

The dev_info.name[] array has space for RIO_MAX_DEVNAME_SZ + 1
characters.  But the problem here is that we don't ensure that the user
put a NUL terminator on the end of the string.  It could lead to an out
of bounds read.

Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/rapidio/devices/rio_mport_cdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c
b/drivers/rapidio/devices/rio_mport_cdev.c
index 4a4a75fa26d5..3440b3e8e578 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -1690,6 +1690,7 @@ static int rio_mport_add_riodev(struct mport_cdev_priv
*priv,
 
 	if (copy_from_user(&dev_info, arg, sizeof(dev_info)))
 		return -EFAULT;
+	dev_info.name[sizeof(dev_info.name) - 1] = '\0';
 
 	rmcd_debug(RDEV, "name:%s ct:0x%x did:0x%x hc:0x%x", dev_info.name,
 		   dev_info.comptag, dev_info.destid, dev_info.hopcount);
@@ -1821,6 +1822,7 @@ static int rio_mport_del_riodev(struct mport_cdev_priv
*priv, void __user *arg)
 
 	if (copy_from_user(&dev_info, arg, sizeof(dev_info)))
 		return -EFAULT;
+	dev_info.name[sizeof(dev_info.name) - 1] = '\0';
 
 	mport = priv->md->mport;
 
-- 
2.20.1