[PATCH 6.6 131/186] net: ethernet: cortina: Drop half-assembled SKB

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

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andreas Haarmann-Thiemann <eitschman@nebelreich.de>

[ 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>
---
 drivers/net/ethernet/cortina/gemini.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 02beed666fa63..0071f27d2d6c1 100644
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -1498,6 +1498,11 @@ 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;
-- 
2.53.0