From 51c96a561f244e25a4a2afc7a48b92b4adf8050d Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sun, 6 Jun 2021 17:24:22 +0300 Subject: [PATCH] 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 Acked-by: Moshe Shemesh Signed-off-by: David S. Miller --- net/ethtool/eeprom.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c index 2a6733a..5d38e90 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; -- 2.7.4