netdev - [PATCH 1/3] net: ethernet: ti: am65-cpsw: Fix max mtu to fit ethernet frames

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

Message-ID: <20240102081825.14635-2-jorge.sanjuangarcia@duagon.com>
Date: Tue, 2 Jan 2024 08:19:10 +0000
From: Sanjuán García, Jorge
	<Jorge.SanjuanGarcia@...gon.com>
To: "davem@...emloft.net" <davem@...emloft.net>, "edumazet@...gle.com"
	<edumazet@...gle.com>, "kuba@...nel.org" <kuba@...nel.org>,
	"pabeni@...hat.com" <pabeni@...hat.com>
CC: "s-vadapalli@...com" <s-vadapalli@...com>, "grygorii.strashko@...com"
	<grygorii.strashko@...com>, "netdev@...r.kernel.org"
	<netdev@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, Sanjuán García, Jorge
	<Jorge.SanjuanGarcia@...gon.com>
Subject: [PATCH 1/3] net: ethernet: ti: am65-cpsw: Fix max mtu to fit ethernet
 frames

The value of AM65_CPSW_MAX_PACKET_SIZE represents the maximum length
of a received frame. This value is written to the register
AM65_CPSW_PORT_REG_RX_MAXLEN.

The maximum MTU configured on the network device should then leave
some room for the ethernet headers and frame check. Otherwise, if
the network interface is configured to its maximum mtu possible,
the frames will be larger than AM65_CPSW_MAX_PACKET_SIZE and will
get dropped as oversized.

Fixes: 93a76530316a ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver")
Signed-off-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@...gon.com>
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 7651f90f51f2..378d69b8cb14 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -2196,7 +2196,8 @@ am65_cpsw_nuss_init_port_ndev(struct am65_cpsw_common *common, u32 port_idx)
 	eth_hw_addr_set(port->ndev, port->slave.mac_addr);
 
 	port->ndev->min_mtu = AM65_CPSW_MIN_PACKET_SIZE;
-	port->ndev->max_mtu = AM65_CPSW_MAX_PACKET_SIZE;
+	port->ndev->max_mtu = AM65_CPSW_MAX_PACKET_SIZE -
+			      (VLAN_ETH_HLEN + ETH_FCS_LEN);
 	port->ndev->hw_features = NETIF_F_SG |
 				  NETIF_F_RXCSUM |
 				  NETIF_F_HW_CSUM |
-- 
2.34.1