From 156e0b1a8112b76e351684ac948c59757037ac36 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 16 Jul 2019 16:30:03 -0700
Subject: [PATCH] drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
Git-commit: 156e0b1a8112b76e351684ac948c59757037ac36
Patch-mainline: v5.3-rc1
References: bsc#1051510

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.

Link: http://lkml.kernel.org/r/20190529110601.GB19119@mwanda
Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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 ce7a90e68042..8155f59ece38 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -1686,6 +1686,7 @@ 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);
@@ -1817,6 +1818,7 @@ 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;
 
-- 
2.16.4