net: ethernet: cortina: Drop half-assembled SKB

[ Upstream commit b266bacba796ff5c4dcd2ae2fc08aacf7ab39153 ]

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: 4d5ae32f5e1e ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 47072fbabcaeea4e12fb5b3214925776159e2e78..8fee13bd056ade2484210342359421a9665ee125 100644 (file)
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -1493,6 +1493,11 @@ 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;