diff mbox series

cavium/liquidio: replace deprecated strncpy with strscpy

Message ID 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-octeon_device-c-v1-1-9a207cef9438@google.com
State New
Headers
Series cavium/liquidio: replace deprecated strncpy with strscpy |

Commit Message

Justin Stitt Oct. 5, 2023, 10:52 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 `app_name` to be NUL-terminated:
	dev_info(&oct->pci_dev->dev,
		 "Running %s (%llu Hz)\n",
		 app_name, CVM_CAST64(cs->corefreq));
... and it seems NUL-padding is not required, let's opt for strscpy().

For `oct->boardinfo.name/serial_number` let's opt for strscpy() as well
since it is expected to be NUL-terminated and does not require
NUL-padding as `oct` is zero-initialized in octeon_device.c +707:
|       buf = vzalloc(size);
|       if (!buf)
|       	return NULL;
|
|       oct = (struct octeon_device *)buf;

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
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/cavium/liquidio/octeon_device.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)


---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-octeon_device-c-3579264bf805

Best regards,
--
Justin Stitt <justinstitt@google.com>

Comments

Kees Cook Oct. 5, 2023, 11:22 p.m. UTC | #1 
On Thu, Oct 05, 2023 at 10:52:34PM +0000, Justin Stitt wrote:
> `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 `app_name` to be NUL-terminated:
> 	dev_info(&oct->pci_dev->dev,
> 		 "Running %s (%llu Hz)\n",
> 		 app_name, CVM_CAST64(cs->corefreq));
> ... and it seems NUL-padding is not required, let's opt for strscpy().
> 
> For `oct->boardinfo.name/serial_number` let's opt for strscpy() as well
> since it is expected to be NUL-terminated and does not require
> NUL-padding as `oct` is zero-initialized in octeon_device.c +707:
> |       buf = vzalloc(size);
> |       if (!buf)
> |       	return NULL;
> |
> |       oct = (struct octeon_device *)buf;
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> 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/cavium/liquidio/octeon_device.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_device.c b/drivers/net/ethernet/cavium/liquidio/octeon_device.c
> index 364f4f912dc2..6b6cb73482d7 100644
> --- a/drivers/net/ethernet/cavium/liquidio/octeon_device.c
> +++ b/drivers/net/ethernet/cavium/liquidio/octeon_device.c
> @@ -1217,10 +1217,10 @@ int octeon_core_drv_init(struct octeon_recv_info *recv_info, void *buf)
>  		goto core_drv_init_err;
>  	}
>  
> -	strncpy(app_name,
> +	strscpy(app_name,
>  		get_oct_app_string(
>  		(u32)recv_pkt->rh.r_core_drv_init.app_mode),
> -		sizeof(app_name) - 1);
> +		sizeof(app_name));

Direct replacement, good.

>  	oct->app_mode = (u32)recv_pkt->rh.r_core_drv_init.app_mode;
>  	if (recv_pkt->rh.r_core_drv_init.app_mode == CVM_DRV_NIC_APP) {
>  		oct->fw_info.max_nic_ports =
> @@ -1257,9 +1257,10 @@ int octeon_core_drv_init(struct octeon_recv_info *recv_info, void *buf)
>  	memcpy(cs, get_rbd(
>  	       recv_pkt->buffer_ptr[0]) + OCT_DROQ_INFO_SIZE, sizeof(*cs));
>  
> -	strncpy(oct->boardinfo.name, cs->boardname, OCT_BOARD_NAME);
> -	strncpy(oct->boardinfo.serial_number, cs->board_serial_number,
> -		OCT_SERIAL_LEN);
> +	strscpy(oct->boardinfo.name, cs->boardname,
> +		    sizeof(oct->boardinfo.name));
> +	strscpy(oct->boardinfo.serial_number, cs->board_serial_number,
> +		    sizeof(oct->boardinfo.serial_number));

struct octeon_board_info {
        char name[OCT_BOARD_NAME];
        char serial_number[OCT_SERIAL_LEN];

Good, sizeof()s match.

Reviewed-by: Kees Cook <keescook@chromium.org>
patchwork-bot+netdevbpf@kernel.org Oct. 10, 2023, 2:50 a.m. UTC | #2 
Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 05 Oct 2023 22:52:34 +0000 you wrote:
> `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 `app_name` to be NUL-terminated:
> 	dev_info(&oct->pci_dev->dev,
> 		 "Running %s (%llu Hz)\n",
> 		 app_name, CVM_CAST64(cs->corefreq));
> ... and it seems NUL-padding is not required, let's opt for strscpy().
> 
> [...]

Here is the summary with links:
  - cavium/liquidio: replace deprecated strncpy with strscpy
    https://git.kernel.org/netdev/net-next/c/c04235395595

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_device.c b/drivers/net/ethernet/cavium/liquidio/octeon_device.c
index 364f4f912dc2..6b6cb73482d7 100644
--- a/drivers/net/ethernet/cavium/liquidio/octeon_device.c
+++ b/drivers/net/ethernet/cavium/liquidio/octeon_device.c
@@ -1217,10 +1217,10 @@  int octeon_core_drv_init(struct octeon_recv_info *recv_info, void *buf)
 		goto core_drv_init_err;
 	}
 
-	strncpy(app_name,
+	strscpy(app_name,
 		get_oct_app_string(
 		(u32)recv_pkt->rh.r_core_drv_init.app_mode),
-		sizeof(app_name) - 1);
+		sizeof(app_name));
 	oct->app_mode = (u32)recv_pkt->rh.r_core_drv_init.app_mode;
 	if (recv_pkt->rh.r_core_drv_init.app_mode == CVM_DRV_NIC_APP) {
 		oct->fw_info.max_nic_ports =
@@ -1257,9 +1257,10 @@  int octeon_core_drv_init(struct octeon_recv_info *recv_info, void *buf)
 	memcpy(cs, get_rbd(
 	       recv_pkt->buffer_ptr[0]) + OCT_DROQ_INFO_SIZE, sizeof(*cs));
 
-	strncpy(oct->boardinfo.name, cs->boardname, OCT_BOARD_NAME);
-	strncpy(oct->boardinfo.serial_number, cs->board_serial_number,
-		OCT_SERIAL_LEN);
+	strscpy(oct->boardinfo.name, cs->boardname,
+		    sizeof(oct->boardinfo.name));
+	strscpy(oct->boardinfo.serial_number, cs->board_serial_number,
+		    sizeof(oct->boardinfo.serial_number));
 
 	octeon_swap_8B_data((u64 *)cs, (sizeof(*cs) >> 3));