[RESEND PATCH] net: macb: fix NULL dereference due to no pcs_config method

From: Parshuram Thombare <pthombar@cadence.com>
To: <nicolas.ferre@microchip.com>, <kuba@kernel.org>,
	<linux-arm-kernel@lists.infradead.org>, <netdev@vger.kernel.org>
Cc: <Claudiu.Beznea@microchip.com>, <Santiago.Esteban@microchip.com>,
	<andrew@lunn.ch>, <davem@davemloft.net>,
	<linux-kernel@vger.kernel.org>, <linux@armlinux.org.uk>,
	<harini.katakam@xilinx.com>, <michal.simek@xilinx.com>,
	Parshuram Thombare <pthombar@cadence.com>
Subject: [RESEND PATCH] net: macb: fix NULL dereference due to no pcs_config method
Date: Thu, 5 Nov 2020 18:58:33 +0100	[thread overview]
Message-ID: <1604599113-2488-1-git-send-email-pthombar@cadence.com> (raw)

This patch fixes NULL pointer dereference due to NULL pcs_config
in pcs_ops.

Reported-by: Nicolas Ferre <Nicolas.Ferre@microchip.com>
Link: https://lore.kernel.org/netdev/2db854c7-9ffb-328a-f346-f68982723d29@microchip.com/
Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index b7bc160..130a5af 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -633,6 +633,15 @@ static void macb_pcs_an_restart(struct phylink_pcs *pcs)
 	/* Not supported */
 }
 
+static int macb_pcs_config(struct phylink_pcs *pcs,
+			   unsigned int mode,
+			   phy_interface_t interface,
+			   const unsigned long *advertising,
+			   bool permit_pause_to_mac)
+{
+	return 0;
+}
+
 static const struct phylink_pcs_ops macb_phylink_usx_pcs_ops = {
 	.pcs_get_state = macb_usx_pcs_get_state,
 	.pcs_config = macb_usx_pcs_config,
@@ -642,6 +651,7 @@ static const struct phylink_pcs_ops macb_phylink_usx_pcs_ops = {
 static const struct phylink_pcs_ops macb_phylink_pcs_ops = {
 	.pcs_get_state = macb_pcs_get_state,
 	.pcs_an_restart = macb_pcs_an_restart,
+	.pcs_config = macb_pcs_config,
 };
 
 static void macb_mac_config(struct phylink_config *config, unsigned int mode,
@@ -776,10 +786,13 @@ static int macb_mac_prepare(struct phylink_config *config, unsigned int mode,
 
 	if (interface == PHY_INTERFACE_MODE_10GBASER)
 		bp->phylink_pcs.ops = &macb_phylink_usx_pcs_ops;
-	else
+	else if (interface == PHY_INTERFACE_MODE_SGMII)
 		bp->phylink_pcs.ops = &macb_phylink_pcs_ops;
+	else
+		bp->phylink_pcs.ops = NULL;
 
-	phylink_set_pcs(bp->phylink, &bp->phylink_pcs);
+	if (bp->phylink_pcs.ops)
+		phylink_set_pcs(bp->phylink, &bp->phylink_pcs);
 
 	return 0;
 }
-- 
2.7.4

