Subject: [PATCH] net/mlx5: Annotate struct mlx5_flow_handle with __counted_by

From: Kees Cook <[email-masked]>
Date: Tue, 3 Oct 2023 16:17:30 -0700

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 mlx5_flow_handle.

Cc: Saeed Mahameed <[email-masked]>
Cc: Leon Romanovsky <[email-masked]>
Cc: "David S. Miller" <[email-masked]>
Cc: Eric Dumazet <[email-masked]>
Cc: Jakub Kicinski <[email-masked]>
Cc: Paolo Abeni <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
index 4aed1768b85f..78eb6b7097e1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
@@ -181,7 +181,7 @@ struct mlx5_flow_rule {
 
 struct mlx5_flow_handle {
 	int num_rules;
-	struct mlx5_flow_rule *rule[];
+	struct mlx5_flow_rule *rule[] __counted_by(num_rules);
 };
 
 /* Type of children is mlx5_flow_group */
-- 
2.34.1