MISRAC2012-Rule-18.1_d Problem with Ethernet MAC

Question

I have a clasic ethernet MAC address code in my source code:

  netif->hwaddr[0] =  heth.Init.MACAddr[0];
  netif->hwaddr[1] =  heth.Init.MACAddr[1];
  netif->hwaddr[2] =  heth.Init.MACAddr[2];
  netif->hwaddr[3] =  heth.Init.MACAddr[3];
  netif->hwaddr[4] =  heth.Init.MACAddr[4];
  netif->hwaddr[5] =  heth.Init.MACAddr[5];

EDIT:

#define NETIF_MAX_HWADDR_LEN 6U

u8_t hwaddr[NETIF_MAX_HWADDR_LEN];

When I try to do static analyse in my code I get this error all these lines:

How can I solve this ?

Answer 1

The MISRA checker says that you access the array out of bounds, which is obviously also the case:

#define NETIF_MAX_HWADDR_LEN 5U

u8_t hwaddr[NETIF_MAX_HWADDR_LEN];

...
netif->hwaddr[5] =  heth.Init.MACAddr[5];

Arrays are 0-indexed in the C language. Solve this by not declaring too small arrays.