Batch 1: Annotate structs with __counted_by

[PATCH 12/14] net: openvswitch: Annotate struct dp_meter with __counted_by

Posted by Kees Cook 2 years, 2 months ago

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 checking 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 dp_meter.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Pravin B Shelar <pshelar@ovn.org>
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
Cc: dev@openvswitch.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 net/openvswitch/meter.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/openvswitch/meter.h b/net/openvswitch/meter.h
index 013de694221f..ed11cd12b512 100644
--- a/net/openvswitch/meter.h
+++ b/net/openvswitch/meter.h
@@ -39,7 +39,7 @@ struct dp_meter {
 	u32 max_delta_t;
 	u64 used;
 	struct ovs_flow_stats stats;
-	struct dp_meter_band bands[];
+	struct dp_meter_band bands[] __counted_by(n_bands);
 };
 
 struct dp_meter_instance {
-- 
2.34.1

Re: [PATCH 12/14] net: openvswitch: Annotate struct dp_meter with __counted_by

Posted by Gustavo A. R. Silva 2 years, 2 months ago


On 9/22/23 11:28, 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 checking 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 dp_meter.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Pravin B Shelar <pshelar@ovn.org>
> 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
> Cc: dev@openvswitch.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   net/openvswitch/meter.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/openvswitch/meter.h b/net/openvswitch/meter.h
> index 013de694221f..ed11cd12b512 100644
> --- a/net/openvswitch/meter.h
> +++ b/net/openvswitch/meter.h
> @@ -39,7 +39,7 @@ struct dp_meter {
>   	u32 max_delta_t;
>   	u64 used;
>   	struct ovs_flow_stats stats;
> -	struct dp_meter_band bands[];
> +	struct dp_meter_band bands[] __counted_by(n_bands);
>   };
>   
>   struct dp_meter_instance {