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: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
> ---
> 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 <[email protected]>
--
Kees Cook
