netdev - [PATCH net] ibmveth: Fix max MTU limit

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

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

Message-Id: <1592495026-27202-1-git-send-email-tlfalcon@linux.ibm.com>
Date:   Thu, 18 Jun 2020 10:43:46 -0500
From:   Thomas Falcon <tlfalcon@...ux.ibm.com>
To:     netdev@...r.kernel.org
Cc:     linuxppc-dev@...ts.ozlabs.org,
        Thomas Falcon <tlfalcon@...ux.ibm.com>
Subject: [PATCH net] ibmveth: Fix max MTU limit

The max MTU limit defined for ibmveth is not accounting for
virtual ethernet buffer overhead, which is twenty-two additional
bytes set aside for the ethernet header and eight additional bytes
of an opaque handle reserved for use by the hypervisor. Update the
max MTU to reflect this overhead.

Signed-off-by: Thomas Falcon <tlfalcon@...ux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 96d36ae5049e..c5c732601e35 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1715,7 +1715,7 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id)
 	}
 
 	netdev->min_mtu = IBMVETH_MIN_MTU;
-	netdev->max_mtu = ETH_MAX_MTU;
+	netdev->max_mtu = ETH_MAX_MTU - IBMVETH_BUFF_OH;
 
 	memcpy(netdev->dev_addr, mac_addr_p, ETH_ALEN);
 
-- 
2.26.2