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]
Date:   Sat, 18 May 2019 18:58:29 +0300
From:   Ido Schimmel <>
Cc:,,,, Ido Schimmel <>
Subject: [PATCH net 2/2] mlxsw: core: Prevent reading unsupported slave address from SFP EEPROM

From: Vadim Pasternak <>

Prevent reading unsupported slave address from SFP EEPROM by testing
Diagnostic Monitoring Type byte in EEPROM. Read only page zero of
EEPROM, in case this byte is zero.

If some SFP transceiver does not support Digital Optical Monitoring
(DOM), reading SFP EEPROM slave address 0x51 could return an error.
Availability of DOM support is verified by reading from zero page
Diagnostic Monitoring Type byte describing how diagnostic monitoring is
implemented by transceiver. If bit 6 of this byte is set, it indicates
that digital diagnostic monitoring has been implemented. Otherwise it is
not and transceiver could fail to reply to transaction for slave address
0x51 [1010001X (A2h)], which is used to access measurements page.

Such issue has been observed when reading cable MCP2M00-xxxx,
MCP7F00-xxxx, and few others.

Fixes: 2ea109039cd3 ("mlxsw: spectrum: Add support for access cable info via ethtool")
Fixes: 4400081b631a ("mlxsw: spectrum: Fix EEPROM access in case of SFP/SFP+")
Signed-off-by: Vadim Pasternak <>
Acked-by: Jiri Pirko <>
Signed-off-by: Ido Schimmel <>
 drivers/net/ethernet/mellanox/mlxsw/core_env.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_env.c b/drivers/net/ethernet/mellanox/mlxsw/core_env.c
index c1c1965d7acc..72539a9a3847 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_env.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_env.c
@@ -3,6 +3,7 @@
 #include <linux/kernel.h>
 #include <linux/err.h>
+#include <linux/sfp.h>
 #include "core.h"
 #include "core_env.h"
@@ -162,7 +163,7 @@ int mlxsw_env_get_module_info(struct mlxsw_core *mlxsw_core, int module,
-	u8 module_rev_id, module_id;
+	u8 module_rev_id, module_id, diag_mon;
 	unsigned int read_size;
 	int err;
@@ -195,8 +196,21 @@ int mlxsw_env_get_module_info(struct mlxsw_core *mlxsw_core, int module,
+		/* Verify if transceiver provides diagnostic monitoring page */
+		err = mlxsw_env_query_module_eeprom(mlxsw_core, module,
+						    SFP_DIAGMON, 1, &diag_mon,
+						    &read_size);
+		if (err)
+			return err;
+		if (read_size < 1)
+			return -EIO;
 		modinfo->type       = ETH_MODULE_SFF_8472;
-		modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
+		if (diag_mon)
+			modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
+		else
+			modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN / 2;
 		return -EINVAL;

Powered by blists - more mailing lists