[PATCH net v1 1/1] net: usb: asix: ax88772: Increase phy_name size

From: Andy Shevchenko
Date: Tue Mar 18 2025 - 12:18:03 EST


GCC compiler (Debian 14.2.0-17) is not happy about printing
into a short buffer (when build with `make W=1`):

drivers/net/usb/ax88172a.c: In function ‘ax88172a_reset’:
include/linux/phy.h:312:20: error: ‘%s’ directive output may be truncated writing up to 60 bytes into a region of size 20 [-Werror=format-truncation=]

Indeed, the buffer size is chosen based on some assumptions, while
in general the assigned name might not fit. Increase the buffer to
cover maximum length of the parameters. With that, change snprintf()
to use sizeof() instead of hard coded number.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/net/usb/ax88172a.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c
index e47bb125048d..7844eb02a4c7 100644
--- a/drivers/net/usb/ax88172a.c
+++ b/drivers/net/usb/ax88172a.c
@@ -18,7 +18,7 @@
struct ax88172a_private {
struct mii_bus *mdio;
struct phy_device *phydev;
- char phy_name[20];
+ char phy_name[MII_BUS_ID_SIZE + 5];
u16 phy_addr;
u16 oldmode;
int use_embdphy;
@@ -308,7 +308,7 @@ static int ax88172a_reset(struct usbnet *dev)
rx_ctl);

/* Connect to PHY */
- snprintf(priv->phy_name, 20, PHY_ID_FMT,
+ snprintf(priv->phy_name, sizeof(priv->phy_name), PHY_ID_FMT,
priv->mdio->id, priv->phy_addr);

priv->phydev = phy_connect(dev->net, priv->phy_name,
--
2.47.2