[PATCH] net: atheros: replace deprecated strncpy with strscpy

From: Justin Stitt
Date: Wed Oct 04 2023 - 21:29:50 EST


`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 netdev->name to be NUL-terminated based on its use with format
strings and dev_info():
| dev_info(&adapter->pdev->dev,
| "%s link is up %d Mbps %s\n",
| netdev->name, adapter->link_speed,
| adapter->link_duplex == FULL_DUPLEX ?
| "full duplex" : "half duplex");

Furthermore, NUL-padding is not required as netdev is already
zero-initialized through alloc_etherdev().

Considering the above, 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@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: build-tested only.
---
drivers/net/ethernet/atheros/atlx/atl2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/atheros/atlx/atl2.c b/drivers/net/ethernet/atheros/atlx/atl2.c
index 1b487c071cb6..bcfc9488125b 100644
--- a/drivers/net/ethernet/atheros/atlx/atl2.c
+++ b/drivers/net/ethernet/atheros/atlx/atl2.c
@@ -1377,7 +1377,7 @@ static int atl2_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
netdev->watchdog_timeo = 5 * HZ;
netdev->min_mtu = 40;
netdev->max_mtu = ETH_DATA_LEN + VLAN_HLEN;
- strncpy(netdev->name, pci_name(pdev), sizeof(netdev->name) - 1);
+ strscpy(netdev->name, pci_name(pdev), sizeof(netdev->name));

netdev->mem_start = mmio_start;
netdev->mem_end = mmio_start + mmio_len;

---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-atheros-atlx-atl2-c-d876945d6341

Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>