| Message ID | 20231010-netdev-replace-strncpy-resend-as-series-v1-7-caf9f0f2f021@google.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: intel: replace deprecated strncpy uses | expand |
> -----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 7/7] igc: 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 use with format > strings: > | if (q_vector->rx.ring && q_vector->tx.ring) > | sprintf(q_vector->name, "%s-TxRx-%u", netdev->name, > > Furthermore, we do not need NUL-padding as netdev is already > zero-allocated: > | netdev = alloc_etherdev_mq(sizeof(struct igc_adapter), > | IGC_MAX_TX_QUEUES); > ... > 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/igc/igc_main.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 --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 98de34d0ce07..e9bb403bbacf 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -6935,7 +6935,7 @@ static int igc_probe(struct pci_dev *pdev, */ igc_get_hw_control(adapter); - strncpy(netdev->name, "eth%d", IFNAMSIZ); + strscpy(netdev->name, "eth%d", sizeof(netdev->name)); err = register_netdev(netdev); if (err) goto err_register;
`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: | if (q_vector->rx.ring && q_vector->tx.ring) | sprintf(q_vector->name, "%s-TxRx-%u", netdev->name, Furthermore, we do not need NUL-padding as netdev is already zero-allocated: | netdev = alloc_etherdev_mq(sizeof(struct igc_adapter), | IGC_MAX_TX_QUEUES); ... 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/igc/igc_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)