From 51c96a561f244e25a4a2afc7a48b92b4adf8050d Mon Sep 17 00:00:00 2001
From: Ido Schimmel <idosch@nvidia.com>
Date: Sun, 6 Jun 2021 17:24:22 +0300
Subject: ethtool: Fix NULL pointer dereference during module EEPROM dump
When get_module_eeprom_by_page() is not implemented by the driver, NULL
pointer dereference can occur [1].
Fix by testing if get_module_eeprom_by_page() is implemented instead of
get_module_info().
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 0 PID: 251 Comm: ethtool Not tainted 5.13.0-rc3-custom-00940-g3822d0670c9d #989
Call Trace:
eeprom_prepare_data+0x101/0x2d0
ethnl_default_doit+0xc2/0x290
genl_family_rcv_msg_doit+0xdc/0x140
genl_rcv_msg+0xd7/0x1d0
netlink_rcv_skb+0x49/0xf0
genl_rcv+0x1f/0x30
netlink_unicast+0x1f6/0x2c0
netlink_sendmsg+0x1f9/0x400
__sys_sendto+0xe1/0x130
__x64_sys_sendto+0x1b/0x20
do_syscall_64+0x3a/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fixes: c97a31f66ebc ("ethtool: wire in generic SFP module access")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ethtool/eeprom.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'net/ethtool')
diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c
index 2a6733a6449a..5d38e90895ac 100644
--- a/net/ethtool/eeprom.c
+++ b/net/ethtool/eeprom.c
@@ -95,7 +95,7 @@ static int get_module_eeprom_by_page(struct net_device *dev,
if (dev->sfp_bus)
return sfp_get_module_eeprom_by_page(dev->sfp_bus, page_data, extack);
- if (ops->get_module_info)
+ if (ops->get_module_eeprom_by_page)
return ops->get_module_eeprom_by_page(dev, page_data, extack);
return -EOPNOTSUPP;
--
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