lkml.org 
[lkml]   [2023]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH] net: mdio: replace deprecated strncpy with strscpy
From
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect new_bus->id to be NUL-terminated but not NUL-padded based on
its prior assignment through snprintf:
| snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);

Due to this, a suitable replacement is `strscpy` [2] due to the fact
that it guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
drivers/net/mdio/mdio-gpio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mdio/mdio-gpio.c b/drivers/net/mdio/mdio-gpio.c
index 0fb3c2de0845..a1718d646504 100644
--- a/drivers/net/mdio/mdio-gpio.c
+++ b/drivers/net/mdio/mdio-gpio.c
@@ -125,7 +125,7 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
if (bus_id != -1)
snprintf(new_bus->id, MII_BUS_ID_SIZE, "gpio-%x", bus_id);
else
- strncpy(new_bus->id, "gpio", MII_BUS_ID_SIZE);
+ strscpy(new_bus->id, "gpio", sizeof(new_bus->id));

if (pdata) {
new_bus->phy_mask = pdata->phy_mask;
---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231012-strncpy-drivers-net-mdio-mdio-gpio-c-bddd9ed0c630
Best regards,
--
Justin Stitt <justinstitt@google.com>

\
 
 \ /
  Last update: 2023-10-12 23:43    [W:0.098 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site