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[PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

Kees Cook posted 1 patch 3 years, 1 month ago 
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by Kees Cook 3 years, 1 month ago 
Zero-length arrays are deprecated[1]. Replace struct
mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
array. Detected with GCC 13, using -fstrict-flex-arrays=3:

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
 3278 |                         val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
      |                                      ^~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
 2954 |         struct mlxsw_sp_nexthop nexthops[0];
      |                                 ^~~~~~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Ido Schimmel <idosch@nvidia.com>
Cc: Petr Machata <petrm@nvidia.com>
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: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index c22c3ac4e2a1..09e32778b012 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
 	   gateway:1, /* routes using the group use a gateway */
 	   is_resilient:1;
 	struct list_head list; /* member in nh_res_grp_list */
-	struct mlxsw_sp_nexthop nexthops[0];
+	struct mlxsw_sp_nexthop nexthops[];
 #define nh_rif	nexthops[0].rif
 };
 
-- 
2.34.1
Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by patchwork-bot+netdevbpf@kernel.org 3 years ago 
Hello:

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

On Thu,  5 Jan 2023 15:22:29 -0800 you wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
> 
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
>  3278 |                         val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
>       |                                      ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
>  2954 |         struct mlxsw_sp_nexthop nexthops[0];
>       |                                 ^~~~~~~~
> 
> [...]

Here is the summary with links:
  - mlxsw: spectrum_router: Replace 0-length array with flexible array
    https://git.kernel.org/netdev/net/c/2ab6478d1266

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by Gustavo A. R. Silva 3 years, 1 month ago 
On Thu, Jan 05, 2023 at 03:22:29PM -0800, Kees Cook wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
> 
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
>  3278 |                         val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
>       |                                      ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
>  2954 |         struct mlxsw_sp_nexthop nexthops[0];
>       |                                 ^~~~~~~~
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Cc: Ido Schimmel <idosch@nvidia.com>
> Cc: Petr Machata <petrm@nvidia.com>
> 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: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks!
--
Gustavo

> ---
>  drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> index c22c3ac4e2a1..09e32778b012 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> @@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
>  	   gateway:1, /* routes using the group use a gateway */
>  	   is_resilient:1;
>  	struct list_head list; /* member in nh_res_grp_list */
> -	struct mlxsw_sp_nexthop nexthops[0];
> +	struct mlxsw_sp_nexthop nexthops[];
>  #define nh_rif	nexthops[0].rif
>  };
>  
> -- 
> 2.34.1
>
Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by Petr Machata 3 years, 1 month ago 
Kees Cook <keescook@chromium.org> writes:

> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
>  3278 |                         val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
>       |                                      ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
>  2954 |         struct mlxsw_sp_nexthop nexthops[0];
>       |                                 ^~~~~~~~
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Cc: Ido Schimmel <idosch@nvidia.com>
> Cc: Petr Machata <petrm@nvidia.com>
> 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: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> index c22c3ac4e2a1..09e32778b012 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> @@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
>  	   gateway:1, /* routes using the group use a gateway */
>  	   is_resilient:1;
>  	struct list_head list; /* member in nh_res_grp_list */
> -	struct mlxsw_sp_nexthop nexthops[0];
> +	struct mlxsw_sp_nexthop nexthops[];
>  #define nh_rif	nexthops[0].rif
>  };

Thanks. I'll pass this through our nightly and report back.
Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by Petr Machata 3 years, 1 month ago 
Petr Machata <petrm@nvidia.com> writes:

> Kees Cook <keescook@chromium.org> writes:
>
>> Zero-length arrays are deprecated[1]. Replace struct
>> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
>> array.

[...]

> Thanks. I'll pass this through our nightly and report back.

Looking good.

Tested-by: Petr Machata <petrm@nvidia.com>
Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array
Posted by Ido Schimmel 3 years, 1 month ago 
On Thu, Jan 05, 2023 at 03:22:29PM -0800, Kees Cook wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
> 
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
>  3278 |                         val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
>       |                                      ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
>  2954 |         struct mlxsw_sp_nexthop nexthops[0];
>       |                                 ^~~~~~~~
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Cc: Ido Schimmel <idosch@nvidia.com>
> Cc: Petr Machata <petrm@nvidia.com>
> 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: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>

Thanks

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