From ac5e3af9996fb911d4fdff910a8ac3cb7fc63a94 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 26 Oct 2009 01:23:33 +0000 Subject: [PATCH] net: sysfs: ethtool_ops can be NULL commit d519e17e2d01a0ee9abe083019532061b4438065 (net: export device speed and duplex via sysfs) made the wrong assumption that netdev->ethtool_ops was always set. This makes possible to crash kernel and let rtnl in locked state. modprobe dummy ip link set dummy0 up (udev runs and crash) Signed-off-by: Eric Dumazet Acked-by: Andy Gospodarek Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 753c420060df..89de182353b0 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -139,7 +139,9 @@ static ssize_t show_speed(struct device *dev, if (!rtnl_trylock()) return restart_syscall(); - if (netif_running(netdev) && netdev->ethtool_ops->get_settings) { + if (netif_running(netdev) && + netdev->ethtool_ops && + netdev->ethtool_ops->get_settings) { struct ethtool_cmd cmd = { ETHTOOL_GSET }; if (!netdev->ethtool_ops->get_settings(netdev, &cmd)) @@ -158,7 +160,9 @@ static ssize_t show_duplex(struct device *dev, if (!rtnl_trylock()) return restart_syscall(); - if (netif_running(netdev) && netdev->ethtool_ops->get_settings) { + if (netif_running(netdev) && + netdev->ethtool_ops && + netdev->ethtool_ops->get_settings) { struct ethtool_cmd cmd = { ETHTOOL_GSET }; if (!netdev->ethtool_ops->get_settings(netdev, &cmd)) -- 2.30.2