2023-10-03 23:19:11

by Kees Cook

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

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" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
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

2023-10-04 01:53:27

by Gustavo A. R. Silva

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

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" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

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)

2023-10-06 10:41:22

by patchwork-bot+netdevbpf

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

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <[email protected]>:

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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