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

From: Parshuram Thombare
Date: Thu Nov 05 2020 - 09:38:03 EST


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

Fixes: e4e143e26ce8 ("net: macb: add support for high speed interface")
Reported-by: Nicolas Ferre <Nicolas.Ferre@xxxxxxxxxxxxx>
Link: https://lkml.org/lkml/2020/11/4/482
Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
---
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