igb: Initialize mailbox message for VF reset

commit de5dc44 upstream.

When a MAC address is not assigned to the VF, that portion of the message
sent to the VF is not set. The memory, however, is allocated from the
stack meaning that information may be leaked to the VM. Initialize the
message buffer to 0 so that no information is passed to the VM in this
case.

Fixes: 6ddbc4c ("igb: Indicate failure on vf reset for empty mac address")
Reported-by: Akihiko Odaki <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
Reviewed-by: Akihiko Odaki <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: anguy11

drivers/net/ethernet/intel/igb/igb_main.c

@@ -7410,7 +7410,7 @@ static void igb_vf_reset_msg(struct igb_adapter *adapter, u32 vf)
 {
 	struct e1000_hw *hw = &adapter->hw;
 	unsigned char *vf_mac = adapter->vf_data[vf].vf_mac_addresses;
-	u32 reg, msgbuf[3];
+	u32 reg, msgbuf[3] = {};
 	u8 *addr = (u8 *)(&msgbuf[1]);
 
 	/* process all the same items cleared in a function level reset */