Re: [PATCH] igb: replace deprecated strncpy with strscpy

From: Jesse Brandeburg
Date: Tue Oct 10 2023 - 17:22:07 EST


On 10/10/2023 2:07 PM, 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 see that netdev->name is expected to be NUL-terminated based on its
> usage with format strings:
> | sprintf(q_vector->name, "%s-TxRx-%u", netdev->name,
> | q_vector->rx.ring->queue_index);
>
> Furthermore, NUL-padding is not required as netdev is already
> zero-allocated:
> | netdev = alloc_etherdev_mq(sizeof(struct igb_adapter),
> | IGB_MAX_TX_QUEUES);
> ...
> 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.

Please see my comments on the igbvf patch.