From: Eric Dumazet <edumazet@google.com>
Date: Thu, 5 Apr 2018 13:39:26 +0000 (-0700)
Subject: net: fool proof dev_valid_name()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=a9d48205d0aedda021fc3728972a9e9934c2b9de;p=openwrt%2Fstaging%2Fblogic.git

net: fool proof dev_valid_name()

We want to use dev_valid_name() to validate tunnel names,
so better use strnlen(name, IFNAMSIZ) than strlen(name) to make
sure to not upset KASAN.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index 9b04a9fd1dfd..969462ebb296 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1027,7 +1027,7 @@ bool dev_valid_name(const char *name)
 {
 	if (*name == '\0')
 		return false;
-	if (strlen(name) >= IFNAMSIZ)
+	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
 		return false;
 	if (!strcmp(name, ".") || !strcmp(name, ".."))
 		return false;