2020-03-22 21:25:05

by Michal Kubecek

Subject: [PATCH net v2] ethtool: fix reference leak in some *_SET handlers

Andrew noticed that some handlers for *_SET commands leak a netdev
reference if required ethtool_ops callbacks do not exist. A simple
reproducer would be e.g.

ip link add veth1 type veth peer name veth2
ethtool -s veth1 wol g
ip link del veth1

Make sure dev_put() is called when ethtool_ops check fails.

v2: add Fixes tags

Fixes: a53f3d41e4d3 ("ethtool: set link settings with LINKINFO_SET request")
Fixes: bfbcfe2032e7 ("ethtool: set link modes related data with LINKMODES_SET request")
Fixes: e54d04e3afea ("ethtool: set message mask with DEBUG_SET request")
Fixes: 8d425b19b305 ("ethtool: set wake-on-lan settings with WOL_SET request")
Reported-by: Andrew Lunn <[email protected]>
Signed-off-by: Michal Kubecek <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Reviewed-by: Florian Fainelli <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
---
net/ethtool/debug.c | 4 +++-
net/ethtool/linkinfo.c | 4 +++-
net/ethtool/linkmodes.c | 4 +++-
net/ethtool/wol.c | 4 +++-
4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/net/ethtool/debug.c b/net/ethtool/debug.c
index aaef4843e6ba..92599ad7b3c2 100644
--- a/net/ethtool/debug.c
+++ b/net/ethtool/debug.c
@@ -107,8 +107,9 @@ int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info)
if (ret < 0)
return ret;
dev = req_info.dev;
+ ret = -EOPNOTSUPP;
if (!dev->ethtool_ops->get_msglevel || !dev->ethtool_ops->set_msglevel)
- return -EOPNOTSUPP;
+ goto out_dev;

rtnl_lock();
ret = ethnl_ops_begin(dev);
@@ -129,6 +130,7 @@ int ethnl_set_debug(struct sk_buff *skb, struct genl_info *info)
ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
+out_dev:
dev_put(dev);
return ret;
}
diff --git a/net/ethtool/linkinfo.c b/net/ethtool/linkinfo.c
index 5d16cb4e8693..6e9e0b590bb5 100644
--- a/net/ethtool/linkinfo.c
+++ b/net/ethtool/linkinfo.c
@@ -126,9 +126,10 @@ int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info)
if (ret < 0)
return ret;
dev = req_info.dev;
+ ret = -EOPNOTSUPP;
if (!dev->ethtool_ops->get_link_ksettings ||
!dev->ethtool_ops->set_link_ksettings)
- return -EOPNOTSUPP;
+ goto out_dev;

rtnl_lock();
ret = ethnl_ops_begin(dev);
@@ -162,6 +163,7 @@ int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info)
ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
+out_dev:
dev_put(dev);
return ret;
}
diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
index 96f20be64553..18cc37be2d9c 100644
--- a/net/ethtool/linkmodes.c
+++ b/net/ethtool/linkmodes.c
@@ -338,9 +338,10 @@ int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info)
if (ret < 0)
return ret;
dev = req_info.dev;
+ ret = -EOPNOTSUPP;
if (!dev->ethtool_ops->get_link_ksettings ||
!dev->ethtool_ops->set_link_ksettings)
- return -EOPNOTSUPP;
+ goto out_dev;

rtnl_lock();
ret = ethnl_ops_begin(dev);
@@ -370,6 +371,7 @@ int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info)
ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
+out_dev:
dev_put(dev);
return ret;
}
diff --git a/net/ethtool/wol.c b/net/ethtool/wol.c
index e1b8a65b64c4..55e1ecaaf739 100644
--- a/net/ethtool/wol.c
+++ b/net/ethtool/wol.c
@@ -128,8 +128,9 @@ int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info)
if (ret < 0)
return ret;
dev = req_info.dev;
+ ret = -EOPNOTSUPP;
if (!dev->ethtool_ops->get_wol || !dev->ethtool_ops->set_wol)
- return -EOPNOTSUPP;
+ goto out_dev;

rtnl_lock();
ret = ethnl_ops_begin(dev);
@@ -172,6 +173,7 @@ int ethnl_set_wol(struct sk_buff *skb, struct genl_info *info)
ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
+out_dev:
dev_put(dev);
return ret;
}
--
2.25.1

2020-03-24 04:54:16

by David Miller

Subject: Re: [PATCH net v2] ethtool: fix reference leak in some *_SET handlers

From: Michal Kubecek <[email protected]>
Date: Sun, 22 Mar 2020 22:24:21 +0100 (CET)

> Andrew noticed that some handlers for *_SET commands leak a netdev
> reference if required ethtool_ops callbacks do not exist. A simple
> reproducer would be e.g.
>
> ip link add veth1 type veth peer name veth2
> ethtool -s veth1 wol g
> ip link del veth1
>
> Make sure dev_put() is called when ethtool_ops check fails.
>
> v2: add Fixes tags
>
> Fixes: a53f3d41e4d3 ("ethtool: set link settings with LINKINFO_SET request")
> Fixes: bfbcfe2032e7 ("ethtool: set link modes related data with LINKMODES_SET request")
> Fixes: e54d04e3afea ("ethtool: set message mask with DEBUG_SET request")
> Fixes: 8d425b19b305 ("ethtool: set wake-on-lan settings with WOL_SET request")
> Reported-by: Andrew Lunn <[email protected]>
> Signed-off-by: Michal Kubecek <[email protected]>
> Reviewed-by: Andrew Lunn <[email protected]>
> Reviewed-by: Florian Fainelli <[email protected]>
> Reviewed-by: Jakub Kicinski <[email protected]>

Applied, thanks Michal.