From: xypron.glpk@gmx.de <xypron.glpk@gmx.de>
Date: Sat, 15 Apr 2017 13:05:46 +0000 (+0200)
Subject: usbtty: avoid potential NULL pointer dereference
X-Git-Tag: v2025.01-rc5-pxa1908~7155
X-Git-Url: http://git.dujemihanovic.xyz/img/static/%7B%7B%20%24.Site.BaseURL%20%7D%7Dposts/%7B%7B%20%24style.RelPermalink%20%7D%7D?a=commitdiff_plain;h=73be5b3fa73e329ad0d9e12db427cd665e1a483c;p=u-boot.git

usbtty: avoid potential NULL pointer dereference

If current_urb is NULL it should not be dereferenced.

The problem was indicated by cppcheck.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
---

diff --git a/drivers/serial/usbtty.c b/drivers/serial/usbtty.c
index 2e19813643..29799dce93 100644
--- a/drivers/serial/usbtty.c
+++ b/drivers/serial/usbtty.c
@@ -850,6 +850,13 @@ static int write_buffer (circbuf_t * buf)
 	struct urb *current_urb = NULL;
 
 	current_urb = next_urb (device_instance, endpoint);
+
+	if (!current_urb) {
+		TTYERR ("current_urb is NULL, buf->size %d\n",
+		buf->size);
+		return 0;
+	}
+
 	/* TX data still exists - send it now
 	 */
 	if(endpoint->sent < current_urb->actual_length){
@@ -871,12 +878,6 @@ static int write_buffer (circbuf_t * buf)
 		 */
 		while (buf->size > 0) {
 
-			if (!current_urb) {
-				TTYERR ("current_urb is NULL, buf->size %d\n",
-					buf->size);
-				return total;
-			}
-
 			dest = (char*)current_urb->buffer +
 				current_urb->actual_length;