From a714e27ea8bdee2b238748029d31472d0a65b611 Mon Sep 17 00:00:00 2001
From: Claudiu Beznea <claudiu.beznea@microchip.com>
Date: Wed, 14 Apr 2021 14:20:29 +0300
Subject: [PATCH] net: macb: fix the restore of cmp registers

Commit a14d273ba159 ("net: macb: restore cmp registers on resume path")
introduces the restore of CMP registers on resume path. In case the IP
doesn't support type 2 screeners (zero on DCFG8 register) the
struct macb::rx_fs_list::list is not initialized and thus the
list_for_each_entry(item, &bp->rx_fs_list.list, list) loop introduced in
commit a14d273ba159 ("net: macb: restore cmp registers on resume path")
will access an uninitialized list leading to crash. Thus, initialize
the struct macb::rx_fs_list::list without taking into account if the
IP supports type 2 screeners or not.

Fixes: a14d273ba159 ("net: macb: restore cmp registers on resume path")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/cadence/macb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 6e5cf490c01d..0f6a6cb7e98d 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3918,6 +3918,7 @@ static int macb_init(struct platform_device *pdev)
 	reg = gem_readl(bp, DCFG8);
 	bp->max_tuples = min((GEM_BFEXT(SCR2CMP, reg) / 3),
 			GEM_BFEXT(T2SCR, reg));
+	INIT_LIST_HEAD(&bp->rx_fs_list.list);
 	if (bp->max_tuples > 0) {
 		/* also needs one ethtype match to check IPv4 */
 		if (GEM_BFEXT(SCR2ETH, reg) > 0) {
@@ -3928,7 +3929,6 @@ static int macb_init(struct platform_device *pdev)
 			/* Filtering is supported in hw but don't enable it in kernel now */
 			dev->hw_features |= NETIF_F_NTUPLE;
 			/* init Rx flow definitions */
-			INIT_LIST_HEAD(&bp->rx_fs_list.list);
 			bp->rx_fs_list.count = 0;
 			spin_lock_init(&bp->rx_fs_lock);
 		} else
-- 
2.34.1