From 5dac665cf403967bb79a7aeb8c182a621fe617ff Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 31 Jul 2019 19:15:43 +0900
Subject: [PATCH] usb: gadget: udc: renesas_usb3: Fix sysfs interface of "role"
Git-commit: 5dac665cf403967bb79a7aeb8c182a621fe617ff
Patch-mainline: v5.3-rc5
References: bsc#1142635

Since the role_store() uses strncmp(), it's possible to refer
out-of-memory if the sysfs data size is smaller than strlen("host").
This patch fixes it by using sysfs_streq() instead of strncmp().

Fixes: cc995c9ec118 ("usb: gadget: udc: renesas_usb3: add support for usb role swap")
Cc: <stable@vger.kernel.org> # v4.12+
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/gadget/udc/renesas_usb3.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -19,6 +19,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
 
@@ -1903,9 +1904,9 @@ static ssize_t role_store(struct device
 	if (!usb3->driver)
 		return -ENODEV;
 
-	if (!strncmp(buf, "host", strlen("host")))
+	if (sysfs_streq(buf, "host"))
 		new_mode_is_host = true;
-	else if (!strncmp(buf, "peripheral", strlen("peripheral")))
+	else if (sysfs_streq(buf, "peripheral"))
 		new_mode_is_host = false;
 	else
 		return -EINVAL;