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 9b04a9fd1dfd0e065a7fe798dd840a07f0e0a4df..969462ebb296250fe5f3b7c4621e9ba9720a2dbe 100644 (file)
--- 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;