From 8674f8d310215d2bb7469b80e6cfccc044f717b3 Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Mon, 21 Jun 2021 19:42:14 +0300
Subject: [PATCH] net: dsa: assert uniqueness of dsa,member properties
The cross-chip notifiers work by comparing each ds->index against the
info->sw_index value from the notifier. The ds->index is retrieved from
the device tree dsa,member property.
If a single tree cross-chip topology does not declare unique switch IDs,
this will result in hard-to-debug issues/voodoo effects such as the
cross-chip notifier for one switch port also matching the port with the
same number from another switch.
Check in dsa_switch_parse_member_of() whether the DSA switch tree
contains a DSA switch with the index we're preparing to add, before
actually adding it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/dsa/dsa2.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index b71e87909f0e3..ba244fbd9646d 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -1259,6 +1259,13 @@ static int dsa_switch_parse_member_of(struct dsa_switch *ds,
if (!ds->dst)
return -ENOMEM;
+ if (dsa_switch_find(ds->dst->index, ds->index)) {
+ dev_err(ds->dev,
+ "A DSA switch with index %d already exists in tree %d\n",
+ ds->index, ds->dst->index);
+ return -EEXIST;
+ }
+
return 0;
}
--
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