Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct nfp_reprs.

Cc: Simon Horman <simon.horman@corigine.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: oss-drivers@corigine.com
Cc: netdev@vger.kernel.org
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_repr.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
index 48a74accbbd3..77bf4198dbde 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
@@ -18,7 +18,7 @@ struct nfp_port;
  */
 struct nfp_reprs {
 	unsigned int num_reprs;
-	struct net_device __rcu *reprs[];
+	struct net_device __rcu *reprs[] __counted_by(num_reprs);
 };
 
 /**
-- 
2.34.1

Hello:

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

On Tue,  3 Oct 2023 16:18:43 -0700 you wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct nfp_reprs.
> 
> [...]

Here is the summary with links:
  - nfp: Annotate struct nfp_reprs with __counted_by
    https://git.kernel.org/netdev/net-next/c/4514aa9f56fd

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

On Tue, Oct 03, 2023 at 04:18:43PM -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct nfp_reprs.
> 
> Cc: Simon Horman <simon.horman@corigine.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: oss-drivers@corigine.com
> Cc: netdev@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org>
Thanks Kees

Acked-by: Louis Peens <louis.peens@corigine.com>
> ---
>  drivers/net/ethernet/netronome/nfp/nfp_net_repr.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> index 48a74accbbd3..77bf4198dbde 100644
> --- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> @@ -18,7 +18,7 @@ struct nfp_port;
>   */
>  struct nfp_reprs {
>  	unsigned int num_reprs;
> -	struct net_device __rcu *reprs[];
> +	struct net_device __rcu *reprs[] __counted_by(num_reprs);
>  };
>  
>  /**
> -- 
> 2.34.1
>

On 10/4/23 01:18, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct nfp_reprs.
> 
> Cc: Simon Horman <simon.horman@corigine.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: oss-drivers@corigine.com
> Cc: netdev@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
>   drivers/net/ethernet/netronome/nfp/nfp_net_repr.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> index 48a74accbbd3..77bf4198dbde 100644
> --- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
> @@ -18,7 +18,7 @@ struct nfp_port;
>    */
>   struct nfp_reprs {
>   	unsigned int num_reprs;
> -	struct net_device __rcu *reprs[];
> +	struct net_device __rcu *reprs[] __counted_by(num_reprs);
>   };
>   
>   /**