linux-kernel - [PATCH net v4.15..v4.19] net: dsa: Fix NPD checking for br_vlan

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 18 Feb 2019 14:30:11 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, frank-w@...lic-files.de,
        Florian Fainelli <f.fainelli@...il.com>,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...oirfairelinux.com>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH net v4.15..v4.19] net: dsa: Fix NPD checking for br_vlan_enabled()

It is possible for the DSA slave network device not to be part of a
bridge, yet have an upper device like a VLAN device be part of a bridge.
When that VLAN device is enslaved, since it does not define any
switchdev_ops, we will recurse down to the lower/physical port device,
call switchdev_port_obj_add() with a VLAN, and here we will check
br_vlan_enabled() on a NULL dp->bridge_dev, thus causing a NULL pointer
de-reference.

This is no longer a problem upstream after commit d17d9f5e5143
("switchdev: Replace port obj add/del SDO with a notification").

Fixes: 2ea7a679ca2a ("net: dsa: Don't add vlans when vlan filtering is disabled")
Reported-by: Frank Wunderlich <frank-w@...lic-files.de>
Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
---
David,

This affects v4.15..v4.19, but not v5.0-rc1 can you still queue this up
for -stable? Thanks!

 net/dsa/port.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/dsa/port.c b/net/dsa/port.c
index ed0595459df1..792a13068c50 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -255,7 +255,7 @@ int dsa_port_vlan_add(struct dsa_port *dp,
 	if (netif_is_bridge_master(vlan->obj.orig_dev))
 		return -EOPNOTSUPP;

-	if (br_vlan_enabled(dp->bridge_dev))
+	if (dp->bridge_dev && br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_ADD, &info);

 	return 0;
@@ -273,7 +273,7 @@ int dsa_port_vlan_del(struct dsa_port *dp,
 	if (netif_is_bridge_master(vlan->obj.orig_dev))
 		return -EOPNOTSUPP;

-	if (br_vlan_enabled(dp->bridge_dev))
+	if (dp->bridge_dev && br_vlan_enabled(dp->bridge_dev))
 		return dsa_port_notify(dp, DSA_NOTIFIER_VLAN_DEL, &info);

 	return 0;
-- 
2.19.1