[PATCH 4.9 20/42] net: mac802154: Fix a condition in the receive path

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Miquel Raynal <miquel.raynal@bootlin.com>

commit f0da47118c7e93cdbbc6fb403dd729a5f2c90ee3 upstream.

Upon reception, a packet must be categorized, either it's destination is
the host, or it is another host. A packet with no destination addressing
fields may be valid in two situations:
- the packet has no source field: only ACKs are built like that, we
  consider the host as the destination.
- the packet has a valid source field: it is directed to the PAN
  coordinator, as for know we don't have this information we consider we
  are not the PAN coordinator.

There was likely a copy/paste error made during a previous cleanup
because the if clause is now containing exactly the same condition as in
the switch case, which can never be true. In the past the destination
address was used in the switch and the source address was used in the
if, which matches what the spec says.

Cc: stable@vger.kernel.org
Fixes: ae531b9475f6 ("ieee802154: use ieee802154_addr instead of *_sa variants")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220826142954.254853-1-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac802154/rx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -52,7 +52,7 @@ ieee802154_subif_frame(struct ieee802154
 
 	switch (mac_cb(skb)->dest.mode) {
 	case IEEE802154_ADDR_NONE:
-		if (mac_cb(skb)->dest.mode != IEEE802154_ADDR_NONE)
+		if (hdr->source.mode != IEEE802154_ADDR_NONE)
 			/* FIXME: check if we are PAN coordinator */
 			skb->pkt_type = PACKET_OTHERHOST;
 		else