kernel: backport DSA patches fixing null-pointer dereference

[ backport of master commit fbe2c3feaa ]

Backport patches
  381a730182f1 ("net: dsa: Move VLAN filtering syncing out of dsa_switch_bridge_leave")
  108dc8741c20 ("net: dsa: Avoid cross-chip syncing of VLAN filtering")
from upstream (currently in net-next) to fix null-pointer dereference.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [master commit detail]
This commit is contained in:
Marek Behún 2022-03-14 15:39:03 +01:00 committed by Petr Štetiar
parent 180b750c02
commit 28343cfb7d
2 changed files with 143 additions and 0 deletions

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@ -0,0 +1,80 @@
From dee0f71c39afdaa30af7b94af420ca1d5c0f0349 Mon Sep 17 00:00:00 2001
From: Tobias Waldekranz <tobias@waldekranz.com>
Date: Mon, 24 Jan 2022 22:09:43 +0100
Subject: [PATCH 5.4 1/2] net: dsa: Move VLAN filtering syncing out of
dsa_switch_bridge_leave
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
commit 381a730182f1d174e1950cd4e63e885b1c302051 upstream.
Most of dsa_switch_bridge_leave was, in fact, dealing with the syncing
of VLAN filtering for switches on which that is a global
setting. Separate the two phases to prepare for the cross-chip related
bugfix in the following commit.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
net/dsa/switch.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 6a9607518823..dd71e3301b27 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -65,19 +65,12 @@ static int dsa_switch_bridge_join(struct dsa_switch *ds,
return 0;
}
-static int dsa_switch_bridge_leave(struct dsa_switch *ds,
- struct dsa_notifier_bridge_info *info)
+static int dsa_switch_sync_vlan_filtering(struct dsa_switch *ds,
+ struct dsa_notifier_bridge_info *info)
{
bool unset_vlan_filtering = br_vlan_enabled(info->br);
int err, i;
- if (ds->index == info->sw_index && ds->ops->port_bridge_leave)
- ds->ops->port_bridge_leave(ds, info->port, info->br);
-
- if (ds->index != info->sw_index && ds->ops->crosschip_bridge_leave)
- ds->ops->crosschip_bridge_leave(ds, info->sw_index, info->port,
- info->br);
-
/* If the bridge was vlan_filtering, the bridge core doesn't trigger an
* event for changing vlan_filtering setting upon slave ports leaving
* it. That is a good thing, because that lets us handle it and also
@@ -103,6 +96,26 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
if (err && err != EOPNOTSUPP)
return err;
}
+
+ return 0;
+}
+
+static int dsa_switch_bridge_leave(struct dsa_switch *ds,
+ struct dsa_notifier_bridge_info *info)
+{
+ int err;
+
+ if (ds->index == info->sw_index && ds->ops->port_bridge_leave)
+ ds->ops->port_bridge_leave(ds, info->port, info->br);
+
+ if (ds->index != info->sw_index && ds->ops->crosschip_bridge_leave)
+ ds->ops->crosschip_bridge_leave(ds, info->sw_index, info->port,
+ info->br);
+
+ err = dsa_switch_sync_vlan_filtering(ds, info);
+ if (err)
+ return err;
+
return 0;
}
--
2.34.1

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From f6edb463510bd936f143907468fc0bf0762b87bf Mon Sep 17 00:00:00 2001
From: Tobias Waldekranz <tobias@waldekranz.com>
Date: Mon, 24 Jan 2022 22:09:44 +0100
Subject: [PATCH 5.4 2/2] net: dsa: Avoid cross-chip syncing of VLAN filtering
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
commit 108dc8741c203e9d6ce4e973367f1bac20c7192b upstream.
Changes to VLAN filtering are not applicable to cross-chip
notifications.
On a system like this:
.-----. .-----. .-----.
| sw1 +---+ sw2 +---+ sw3 |
'-1-2-' '-1-2-' '-1-2-'
Before this change, upon sw1p1 leaving a bridge, a call to
dsa_port_vlan_filtering would also be made to sw2p1 and sw3p1.
In this scenario:
.---------. .-----. .-----.
| sw1 +---+ sw2 +---+ sw3 |
'-1-2-3-4-' '-1-2-' '-1-2-'
When sw1p4 would leave a bridge, dsa_port_vlan_filtering would be
called for sw2 and sw3 with a non-existing port - leading to array
out-of-bounds accesses and crashes on mv88e6xxx.
Fixes: d371b7c92d19 ("net: dsa: Unset vlan_filtering when ports leave the bridge")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
net/dsa/switch.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index dd71e3301b27..f517d6d7efa2 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -112,9 +112,11 @@ static int dsa_switch_bridge_leave(struct dsa_switch *ds,
ds->ops->crosschip_bridge_leave(ds, info->sw_index, info->port,
info->br);
- err = dsa_switch_sync_vlan_filtering(ds, info);
- if (err)
- return err;
+ if (ds->index == info->sw_index) {
+ err = dsa_switch_sync_vlan_filtering(ds, info);
+ if (err)
+ return err;
+ }
return 0;
}
--
2.34.1