[PATCH] net: bonding: Use strscpy() instead of manually-truncated strncpy()

From: Kees Cook <keescook@chromium.org>
To: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
	kernel test robot <lkp@intel.com>,
	Veaceslav Falico <vfalico@gmail.com>,
	Andy Gospodarek <andy@greyhouse.net>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: [PATCH] net: bonding: Use strscpy() instead of manually-truncated strncpy()
Date: Wed,  2 Jun 2021 11:11:33 -0700	[thread overview]
Message-ID: <20210602181133.3326856-1-keescook@chromium.org> (raw)

Silence this warning by just using strscpy() directly:

drivers/net/bonding/bond_main.c:4877:3: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
    4877 |   strncpy(params->primary, primary, IFNAMSIZ);
         |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202102150705.fdR6obB0-lkp@intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/bonding/bond_main.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index c5a646d06102..ecfc48f2d0d0 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -5329,10 +5329,8 @@ static int bond_check_params(struct bond_params *params)
 			(struct reciprocal_value) { 0 };
 	}
 
-	if (primary) {
-		strncpy(params->primary, primary, IFNAMSIZ);
-		params->primary[IFNAMSIZ - 1] = 0;
-	}
+	if (primary)
+		strscpy(params->primary, primary, sizeof(params->primary));
 
 	memcpy(params->arp_targets, arp_target, sizeof(arp_target));
 
-- 
2.25.1

