diff mbox series

[v1,net-next,6/7] igbvf: replace deprecated strncpy with strscpy

Message ID 20231010-netdev-replace-strncpy-resend-as-series-v1-6-caf9f0f2f021@google.com (mailing list archive)
State Mainlined
Commit a6c78d5f8d5df78c2cf1ce6b0de27649b759c2e0
Headers show
Series net: intel: replace deprecated strncpy uses | expand

Commit Message

Justin Stitt Oct. 10, 2023, 10:26 p.m. UTC
`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 usage with
`strlen` and format strings:
|       if (strlen(netdev->name) < (IFNAMSIZ - 5)) {
|               sprintf(adapter->tx_ring->name, "%s-tx-0", netdev->name);

Moreover, we do not need NUL-padding as netdev is already
zero-allocated:
|       netdev = alloc_etherdev(sizeof(struct igbvf_adapter));
...
alloc_etherdev() -> alloc_etherdev_mq() -> alloc_etherdev_mqs() ->
alloc_netdev_mqs() ...
|       p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);

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@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>

---
Note: build-tested only.
---
 drivers/net/ethernet/intel/igbvf/netdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Pucha, HimasekharX Reddy Oct. 16, 2023, 8:40 a.m. UTC | #1
> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Justin Stitt
> Sent: Wednesday, October 11, 2023 3:57 AM
> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; David S. Miller <davem@davemloft.net>; Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>
> Cc: netdev@vger.kernel.org; Justin Stitt <justinstitt@google.com>; intel-wired-lan@lists.osuosl.org; linux-hardening@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH v1 net-next 6/7] igbvf: replace deprecated strncpy with strscpy
>
> `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 usage with
> `strlen` and format strings:
> |       if (strlen(netdev->name) < (IFNAMSIZ - 5)) {
> |               sprintf(adapter->tx_ring->name, "%s-tx-0", netdev->name);
>
> Moreover, we do not need NUL-padding as netdev is already
> zero-allocated:
> |       netdev = alloc_etherdev(sizeof(struct igbvf_adapter));
> ...
> alloc_etherdev() -> alloc_etherdev_mq() -> alloc_etherdev_mqs() ->
> alloc_netdev_mqs() ...
> |       p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
>
> 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@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
>
> ---
> Note: build-tested only.
> ---
>  drivers/net/ethernet/intel/igbvf/netdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c
index 7ff2752dd763..fd712585af27 100644
--- a/drivers/net/ethernet/intel/igbvf/netdev.c
+++ b/drivers/net/ethernet/intel/igbvf/netdev.c
@@ -2785,7 +2785,7 @@  static int igbvf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	igbvf_set_ethtool_ops(netdev);
 	netdev->watchdog_timeo = 5 * HZ;
-	strncpy(netdev->name, pci_name(pdev), sizeof(netdev->name) - 1);
+	strscpy(netdev->name, pci_name(pdev), sizeof(netdev->name));
 
 	adapter->bd_number = cards_found++;