Re: [PATCH] net: mac802154: Fix a condition in the receive path

On Sun, Aug 28, 2022 at 08:16:20PM -0400, Alexander Aring wrote:

Hi,

On Fri, Aug 26, 2022 at 10:31 AM Miquel Raynal
[off-list ref] wrote:

quoted

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>
---
 net/mac802154/rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index b8ce84618a55..c439125ef2b9 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c

@@ -44,7 +44,7 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,

        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

This patch looks okay but it should not be addressed to stable. Leave
of course the fixes tag.

Why do that?  Do you not want this in the stable tree?

Wpan sends pull requests to net and they have their own way to get
into the stable tree when they are in net.

No, the normal method has been used for quite a while now.

Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.