i40e: add range check to i40e_aq_rc_to_posix

Just to be sure, add a range check to avoid any possible
array index-out-of-bound issues.

CC: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Change-ID: I9323bee6732c2a47599816e1d6c6b3a1f8dcbf54
Signed-off-by: NShannon Nelson <shannon.nelson@intel.com>
Acked-by: NMichal Kosiarz <michal.kosiarz@intel.com>
Tested-by: NJim Young <jamesx.m.young@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_adminq.h

@@ -136,6 +136,8 @@ static inline int i40e_aq_rc_to_posix(u16 aq_rc)
 		-EFBIG,      /* I40E_AQ_RC_EFBIG */
 	};
 
+	if (aq_rc >= ARRAY_SIZE(aq_to_posix))
+		return -ERANGE;
 	return aq_to_posix[aq_rc];
 }
 

drivers/net/ethernet/intel/i40evf/i40e_adminq.h

@@ -136,6 +136,8 @@ static inline int i40e_aq_rc_to_posix(u16 aq_rc)
 		-EFBIG,      /* I40E_AQ_RC_EFBIG */
 	};
 
+	if (aq_rc >= ARRAY_SIZE(aq_to_posix))
+		return -ERANGE;
 	return aq_to_posix[aq_rc];
 }