netdev - [PATCH] bonding: Always assign be16 value to 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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

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

Message-Id: <20230420-bonding-be-vlan-proto-v1-1-754399f51d01@kernel.org>
Date:   Thu, 20 Apr 2023 17:29:08 +0200
From:   Simon Horman <horms@...nel.org>
To:     Jakub Kicinski <kuba@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>
Cc:     Jay Vosburgh <j.vosburgh@...il.com>,
        Andy Gospodarek <andy@...yhouse.net>, netdev@...r.kernel.org
Subject: [PATCH] bonding: Always assign be16 value to vlan_proto

The type of the vlan_proto field is __be16.
And most users of the field use it as such.

In the case of setting or testing the field for the
special VLAN_N_VID value, host byte order is used.
Which seems incorrect.

Address this issue by converting VLAN_N_VID to __be16.

I don't believe this is a bug because VLAN_N_VID in
both little-endian (and big-endian) byte order does
not conflict with any valid values (0 through VLAN_N_VID - 1)
in big-endian byte order.

Reported by sparse as:

 .../bond_main.c:2857:26: warning: restricted __be16 degrades to integer
 .../bond_main.c:2863:20: warning: restricted __be16 degrades to integer
 .../bond_main.c:2939:40: warning: incorrect type in assignment (different base types)
 .../bond_main.c:2939:40:    expected restricted __be16 [usertype] vlan_proto
 .../bond_main.c:2939:40:    got int

No functional changes intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@...nel.org>
---
 drivers/net/bonding/bond_main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index db7e650d9ebb..7f4c75fe58e1 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2854,13 +2854,13 @@ static bool bond_handle_vlan(struct slave *slave, struct bond_vlan_tag *tags,
 	struct net_device *slave_dev = slave->dev;
 	struct bond_vlan_tag *outer_tag = tags;
 
-	if (!tags || tags->vlan_proto == VLAN_N_VID)
+	if (!tags || tags->vlan_proto == cpu_to_be16(VLAN_N_VID))
 		return true;
 
 	tags++;
 
 	/* Go through all the tags backwards and add them to the packet */
-	while (tags->vlan_proto != VLAN_N_VID) {
+	while (tags->vlan_proto != cpu_to_be16(VLAN_N_VID)) {
 		if (!tags->vlan_id) {
 			tags++;
 			continue;
@@ -2936,7 +2936,7 @@ struct bond_vlan_tag *bond_verify_device_path(struct net_device *start_dev,
 		tags = kcalloc(level + 1, sizeof(*tags), GFP_ATOMIC);
 		if (!tags)
 			return ERR_PTR(-ENOMEM);
-		tags[level].vlan_proto = VLAN_N_VID;
+		tags[level].vlan_proto = cpu_to_be16(VLAN_N_VID);
 		return tags;
 	}