net: mscc: ocelot: fix memory leak on ocelot_port_add_txtstamp_skb()

[ Upstream commit 4b01bec25bef62544228bce06db6a3afa5d3d6bb ]

If ocelot_port_add_txtstamp_skb() fails, for example due to a full PTP
timestamp FIFO, we must undo the skb_clone_sk() call with kfree_skb().
Otherwise, the reference to the skb clone is lost.

Fixes: 52849bcf0029 ("net: mscc: ocelot: avoid overflowing the PTP timestamp FIFO")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241205145519.1236778-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mscc/ocelot_ptp.c b/drivers/net/ethernet/mscc/ocelot_ptp.c
index cb32234a5bf1bcc01a827bf0a6450d7d2c37dfe3..3c22652879ac209a981592b76749aea920446ae7 100644 (file)
--- a/drivers/net/ethernet/mscc/ocelot_ptp.c
+++ b/drivers/net/ethernet/mscc/ocelot_ptp.c
@@ -692,8 +692,10 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
                        return -ENOMEM;
 
                err = ocelot_port_add_txtstamp_skb(ocelot, port, *clone);
-               if (err)
+               if (err) {
+                       kfree_skb(*clone);
                        return err;
+               }
 
                OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
                OCELOT_SKB_CB(*clone)->ptp_class = ptp_class;