2023-10-03 23:18:45

by Kees Cook

Subject: [PATCH] nexthop: Annotate struct nh_res_table 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 nh_res_table.

Cc: David Ahern <[email protected]>
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/nexthop.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index 5dc4b4bba8a5..09f9a732e640 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -92,7 +92,7 @@ struct nh_res_table {
u32 unbalanced_timer;

u16 num_nh_buckets;
- struct nh_res_bucket nh_buckets[];
+ struct nh_res_bucket nh_buckets[] __counted_by(num_nh_buckets);
};

struct nh_grp_entry {
--
2.34.1

2023-10-03 23:36:54

by Gustavo A. R. Silva

Subject: Re: [PATCH] nexthop: Annotate struct nh_res_table 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 nh_res_table.
>
> Cc: David Ahern <[email protected]>
> 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/nexthop.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/nexthop.h b/include/net/nexthop.h
> index 5dc4b4bba8a5..09f9a732e640 100644
> --- a/include/net/nexthop.h
> +++ b/include/net/nexthop.h
> @@ -92,7 +92,7 @@ struct nh_res_table {
> u32 unbalanced_timer;
>
> u16 num_nh_buckets;
> - struct nh_res_bucket nh_buckets[];
> + struct nh_res_bucket nh_buckets[] __counted_by(num_nh_buckets);
> };
>
> struct nh_grp_entry {

2023-10-03 23:37:12

by David Ahern

Subject: Re: [PATCH] nexthop: Annotate struct nh_res_table with __counted_by

On 10/3/23 5:18 PM, 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 nh_res_table.
>
> Cc: David Ahern <[email protected]>
> 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/nexthop.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Reviewed-by: David Ahern <[email protected]>

2023-10-06 01:41:13

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] nexthop: Annotate struct nh_res_table with __counted_by

Hello:

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

On Tue, 3 Oct 2023 16:18:13 -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 nh_res_table.
>
> [...]

Here is the summary with links:
- nexthop: Annotate struct nh_res_table with __counted_by
https://git.kernel.org/netdev/net-next/c/2253bb3ff242

You are awesome, thank you!
--
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