net: don't call strlen on non-terminated string in dev_set_alias()

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

1 files changed, 2 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index fca407b4a6ea..84e1e86a4bce 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1253,8 +1253,9 @@ int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
         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;
 }