[PATCH 3.18 05/36] net: dont call strlen on non-terminated string in dev_set_alias()

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexander Potapenko <gli...@google.com>


[ Upstream commit c28294b941232931fbd714099798eb7aa7e865d7 ]

KMSAN reported a use of uninitialized memory in dev_set_alias(),
which was caused by calling strlcpy() (which in turn called strlen())
on the user-supplied non-terminated string.

Signed-off-by: Alexander Potapenko <gli...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/core/dev.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1194,8 +1194,9 @@ int dev_set_alias(struct net_device *dev
        if (!new_ifalias)
                return -ENOMEM;
        dev->ifalias = new_ifalias;
+       memcpy(dev->ifalias, alias, len);
+       dev->ifalias[len] = 0;
 
-       strlcpy(dev->ifalias, alias, len+1);
        return len;
 }