[PATCH 09/22] net: niu: fix format string overflow warning:

From: Arnd Bergmann
Date: Fri Jul 14 2017 - 08:11:08 EST


We get a warning for the port_name string that might be longer than
six characters if we had more than 10 ports:

drivers/net/ethernet/sun/niu.c: In function 'niu_put_parent':
drivers/net/ethernet/sun/niu.c:9563:21: error: '%d' directive writing between 1 and 3 bytes into a region of size 2 [-Werror=format-overflow=]
sprintf(port_name, "port%d", port);
^~~~~~~~
drivers/net/ethernet/sun/niu.c:9563:21: note: directive argument in the range [0, 255]
drivers/net/ethernet/sun/niu.c:9563:2: note: 'sprintf' output between 6 and 8 bytes into a destination of size 6
sprintf(port_name, "port%d", port);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/sun/niu.c: In function 'niu_pci_init_one':
drivers/net/ethernet/sun/niu.c:9538:22: error: '%d' directive writing between 1 and 3 bytes into a region of size 2 [-Werror=format-overflow=]
sprintf(port_name, "port%d", port);
^~~~~~~~
drivers/net/ethernet/sun/niu.c:9538:22: note: directive argument in the range [0, 255]
drivers/net/ethernet/sun/niu.c:9538:3: note: 'sprintf' output between 6 and 8 bytes into a destination of size 6

While we know that the port number is small, there is no harm in
making the format string two bytes longer to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/ethernet/sun/niu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/sun/niu.c b/drivers/net/ethernet/sun/niu.c
index 46cb7f8955a2..4bb04aaf9650 100644
--- a/drivers/net/ethernet/sun/niu.c
+++ b/drivers/net/ethernet/sun/niu.c
@@ -9532,7 +9532,7 @@ static struct niu_parent *niu_get_parent(struct niu *np,
p = niu_new_parent(np, id, ptype);

if (p) {
- char port_name[6];
+ char port_name[8];
int err;

sprintf(port_name, "port%d", port);
@@ -9553,7 +9553,7 @@ static void niu_put_parent(struct niu *np)
{
struct niu_parent *p = np->parent;
u8 port = np->port;
- char port_name[6];
+ char port_name[8];

BUG_ON(!p || p->ports[port] != np);

--
2.9.0