net/i40e: Replace 0-length array with flexible array

[PATCH] net/i40e: Replace 0-length array with flexible array

Posted by Kees Cook 2 years, 8 months ago

Zero-length arrays are deprecated[1]. Replace struct i40e_lump_tracking's
"list" 0-length array with a flexible array. Detected with GCC 13,
using -fstrict-flex-arrays=3:

In function 'i40e_put_lump',
    inlined from 'i40e_clear_interrupt_scheme' at drivers/net/ethernet/intel/i40e/i40e_main.c:5145:2:
drivers/net/ethernet/intel/i40e/i40e_main.c:278:27: warning: array subscript <unknown> is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-Warray-bounds=]
  278 |                 pile->list[i] = 0;
      |                 ~~~~~~~~~~^~~
drivers/net/ethernet/intel/i40e/i40e.h: In function 'i40e_clear_interrupt_scheme':
drivers/net/ethernet/intel/i40e/i40e.h:179:13: note: while referencing 'list'
  179 |         u16 list[0];
      |             ^~~~

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

Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.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: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/intel/i40e/i40e.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 60e351665c70..3a1c28ca5bb4 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -176,7 +176,7 @@ enum i40e_interrupt_policy {
 
 struct i40e_lump_tracking {
 	u16 num_entries;
-	u16 list[0];
+	u16 list[];
 #define I40E_PILE_VALID_BIT  0x8000
 #define I40E_IWARP_IRQ_PILE_ID  (I40E_PILE_VALID_BIT - 2)
 };
-- 
2.34.1

RE: [Intel-wired-lan] [PATCH] net/i40e: Replace 0-length array with flexible array

Posted by G, GurucharanX 2 years, 7 months ago


> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Kees Cook
> Sent: Friday, January 6, 2023 5:16 AM
> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>
> Cc: Kees Cook <keescook@chromium.org>; intel-wired-lan@lists.osuosl.org;
> Gustavo A. R. Silva <gustavoars@kernel.org>; linux-kernel@vger.kernel.org;
> Eric Dumazet <edumazet@google.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; linux-hardening@vger.kernel.org;
> netdev@vger.kernel.org; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni
> <pabeni@redhat.com>; David S. Miller <davem@davemloft.net>
> Subject: [Intel-wired-lan] [PATCH] net/i40e: Replace 0-length array with
> flexible array
> 
> Zero-length arrays are deprecated[1]. Replace struct i40e_lump_tracking's
> "list" 0-length array with a flexible array. Detected with GCC 13, using -fstrict-
> flex-arrays=3:
> 
> In function 'i40e_put_lump',
>     inlined from 'i40e_clear_interrupt_scheme' at
> drivers/net/ethernet/intel/i40e/i40e_main.c:5145:2:
> drivers/net/ethernet/intel/i40e/i40e_main.c:278:27: warning: array subscript
> <unknown> is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-
> Warray-bounds=]
>   278 |                 pile->list[i] = 0;
>       |                 ~~~~~~~~~~^~~
> drivers/net/ethernet/intel/i40e/i40e.h: In function
> 'i40e_clear_interrupt_scheme':
> drivers/net/ethernet/intel/i40e/i40e.h:179:13: note: while referencing 'list'
>   179 |         u16 list[0];
>       |             ^~~~
> 
> [1]
> https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-
> length-and-one-element-arrays
> 
> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
> Cc: Tony Nguyen <anthony.l.nguyen@intel.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: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/net/ethernet/intel/i40e/i40e.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)

Re: [PATCH] net/i40e: Replace 0-length array with flexible array

Posted by Jiri Pirko 2 years, 8 months ago

Fri, Jan 06, 2023 at 12:46:01AM CET, keescook@chromium.org wrote:
>Zero-length arrays are deprecated[1]. Replace struct i40e_lump_tracking's
>"list" 0-length array with a flexible array. Detected with GCC 13,
>using -fstrict-flex-arrays=3:
>
>In function 'i40e_put_lump',
>    inlined from 'i40e_clear_interrupt_scheme' at drivers/net/ethernet/intel/i40e/i40e_main.c:5145:2:
>drivers/net/ethernet/intel/i40e/i40e_main.c:278:27: warning: array subscript <unknown> is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-Warray-bounds=]
>  278 |                 pile->list[i] = 0;
>      |                 ~~~~~~~~~~^~~
>drivers/net/ethernet/intel/i40e/i40e.h: In function 'i40e_clear_interrupt_scheme':
>drivers/net/ethernet/intel/i40e/i40e.h:179:13: note: while referencing 'list'
>  179 |         u16 list[0];
>      |             ^~~~
>
>[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
>Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
>Cc: Tony Nguyen <anthony.l.nguyen@intel.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: intel-wired-lan@lists.osuosl.org
>Cc: netdev@vger.kernel.org
>Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [Intel-wired-lan] [PATCH] net/i40e: Replace 0-length array with flexible array

Posted by Gustavo A. R. Silva 2 years, 8 months ago

On Thu, Jan 05, 2023 at 03:46:01PM -0800, Kees Cook wrote:
> Zero-length arrays are deprecated[1]. Replace struct i40e_lump_tracking's
> "list" 0-length array with a flexible array. Detected with GCC 13,
> using -fstrict-flex-arrays=3:
> 
> In function 'i40e_put_lump',
>     inlined from 'i40e_clear_interrupt_scheme' at drivers/net/ethernet/intel/i40e/i40e_main.c:5145:2:
> drivers/net/ethernet/intel/i40e/i40e_main.c:278:27: warning: array subscript <unknown> is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-Warray-bounds=]
>   278 |                 pile->list[i] = 0;
>       |                 ~~~~~~~~~~^~~
> drivers/net/ethernet/intel/i40e/i40e.h: In function 'i40e_clear_interrupt_scheme':
> drivers/net/ethernet/intel/i40e/i40e.h:179:13: note: while referencing 'list'
>   179 |         u16 list[0];
>       |             ^~~~
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
> Cc: Tony Nguyen <anthony.l.nguyen@intel.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: intel-wired-lan@lists.osuosl.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/intel/i40e/i40e.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
> index 60e351665c70..3a1c28ca5bb4 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
> @@ -176,7 +176,7 @@ enum i40e_interrupt_policy {
>  
>  struct i40e_lump_tracking {
>  	u16 num_entries;
> -	u16 list[0];
> +	u16 list[];
>  #define I40E_PILE_VALID_BIT  0x8000
>  #define I40E_IWARP_IRQ_PILE_ID  (I40E_PILE_VALID_BIT - 2)
>  };
> -- 
> 2.34.1
> 
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> Intel-wired-lan@osuosl.org
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