Re: [PATCH] be2net: Remove potential access to the zero address

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

On Wed, Apr 16, 2025 at 10:55:47AM +0000, Ваторопин Андрей wrote:
> From: Andrey Vatoropin <a.vatoropin@crpt.ru>
> 
> At the moment of calling the function be_cmd_get_mac_from_list() with the
> following parameters:
> be_cmd_get_mac_from_list(adapter, mac, &pmac_valid, NULL, 
> 					adapter->if_handle, 0);

Looks like pmac_valid needs to be false to reach *pmac_id assign.

> 
> The parameter "pmac_id" equals NULL.
> 
> Then, if "mac_addr_size" equals four bytes, there is a possibility of
> accessing the zero address via the pointer "pmac_id".
> 
> Add an extra check for the pointer "pmac_id" to avoid accessing the zero
> address.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>        
> Fixes: e5e1ee894615 ("be2net: Use new implementation of get mac list command")
> Signed-off-by: Andrey Vatoropin <a.vatoropin@crpt.ru>
> ---
>  drivers/net/ethernet/emulex/benet/be_cmds.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c
> index 51b8377edd1d..be5bbf6881b8 100644
> --- a/drivers/net/ethernet/emulex/benet/be_cmds.c
> +++ b/drivers/net/ethernet/emulex/benet/be_cmds.c
> @@ -3757,7 +3757,7 @@ int be_cmd_get_mac_from_list(struct be_adapter *adapter, u8 *mac,
>  			/* mac_id is a 32 bit value and mac_addr size
>  			 * is 6 bytes
>  			 */
> -			if (mac_addr_size == sizeof(u32)) {
> +			if (pmac_id && mac_addr_size == sizeof(u32)) {
>  				*pmac_id_valid = true;
>  				mac_id = mac_entry->mac_addr_id.s_mac_id.mac_id;
>  				*pmac_id = le32_to_cpu(mac_id);

Thanks for fixing.
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>

> -- 
> 2.43.0