net: ethernet: cortina: Drop half-assembled SKB

In gmac_rx() (drivers/net/ethernet/cortina/gemini.c), when
gmac_get_queue_page() returns NULL for the second page of a multi-page
fragment, the driver logs an error and continues — but does not free the
partially assembled skb that was being assembled via napi_build_skb() /
napi_get_frags().

Free the in-progress partially assembled skb via napi_free_frags()
and increase the number of dropped frames appropriately
and assign the skb pointer NULL to make sure it is not lingering
around, matching the pattern already used elsewhere in the driver.

Fixes: 4d5ae32 ("net: ethernet: Add a driver for Gemini gigabit ethernet")
Signed-off-by: Andreas Haarmann-Thiemann <eitschman@nebelreich.de>
Signed-off-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260505-gemini-ethernet-fix-v2-1-997c31d06079@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Eitschman

drivers/net/ethernet/cortina/gemini.c

@@ -1491,6 +1491,11 @@ static unsigned int gmac_rx(struct net_device *netdev, unsigned int budget)
 		gpage = gmac_get_queue_page(geth, port, mapping + PAGE_SIZE);
 		if (!gpage) {
 			dev_err(geth->dev, "could not find mapping\n");
+			if (skb) {
+				napi_free_frags(&port->napi);
+				port->stats.rx_dropped++;
+				skb = NULL;
+			}
 			continue;
 		}
 		page = gpage->page;