[PATCH] flow_offload: Annotate struct flow_action_entry with __counted_by

[PATCH] flow_offload: Annotate struct flow_action_entry with __counted_by

[Kees Cook]

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 flow_action_entry.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.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>
---
 include/net/flow_offload.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
index 9efa9a59e81f..314087a5e181 100644
--- a/include/net/flow_offload.h
+++ b/include/net/flow_offload.h
@@ -333,7 +333,7 @@ struct flow_action_entry {
 
 struct flow_action {
 	unsigned int			num_entries;
-	struct flow_action_entry	entries[];
+	struct flow_action_entry	entries[] __counted_by(num_entries);
 };
 
 static inline bool flow_action_has_entries(const struct flow_action *action)
-- 
2.34.1

Re: [PATCH] flow_offload: Annotate struct flow_action_entry with __counted_by

[Gustavo A. R. Silva]

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 flow_action_entry.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.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

> ---
>   include/net/flow_offload.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
> index 9efa9a59e81f..314087a5e181 100644
> --- a/include/net/flow_offload.h
> +++ b/include/net/flow_offload.h
> @@ -333,7 +333,7 @@ struct flow_action_entry {
>   
>   struct flow_action {
>   	unsigned int			num_entries;
> -	struct flow_action_entry	entries[];
> +	struct flow_action_entry	entries[] __counted_by(num_entries);
>   };
>   
>   static inline bool flow_action_has_entries(const struct flow_action *action)

Re: [PATCH] flow_offload: Annotate struct flow_action_entry with __counted_by

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Tue,  3 Oct 2023 16:18:33 -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 flow_action_entry.
> 
> [...]

Here is the summary with links:
  - flow_offload: Annotate struct flow_action_entry with __counted_by
    https://git.kernel.org/netdev/net-next/c/99474727d5d5

You are awesome, thank you!
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