wifi: mac80211: drop invalid source address OCB frames

In OCB, don't accept frames from invalid source addresses
(and in particular don't try to create stations for them),
drop the frames instead.

Reported-by: [e-mail]
Closes: https://lore.kernel.org/r/[e-mail]/
Signed-off-by: Johannes Berg <[e-mail]>
Tested-by: [e-mail]
Link: https://patch.msgid.link/20250616171838.7433379cab5d.I47444d63c72a0bd58d2e2b67bb99e1fea37eec6f@changeid
Signed-off-by: Johannes Berg <[e-mail]>

net/mac80211/rx.c

···
 		if (!multicast &&
 		    !ether_addr_equal(sdata->dev->dev_addr, hdr->addr1))
 			return false;
+		/* reject invalid/our STA address */
+		if (!is_valid_ether_addr(hdr->addr2) ||
+		    ether_addr_equal(sdata->dev->dev_addr, hdr->addr2))
+			return false;
 		if (!rx->sta) {
 			int rate_idx;
 			if (status->encoding != RX_ENC_LEGACY)