Gitweb: http://git.kernel.org/linus/bf988435bd5b53529f4408a8efb1f433f6ddfda9
Commit: bf988435bd5b53529f4408a8efb1f433f6ddfda9
Parent: db048b69037e7fa6a7d9e95a1271a50dc08ae233
Author: Ben Hutchings <bhutchings@solarflare.com>
AuthorDate: Mon Jun 28 08:45:58 2010 +0000
Committer: David S. Miller <davem@davemloft.net>
CommitDate: Tue Jun 29 01:00:29 2010 -0700
ethtool: Fix potential user buffer overflow for ETHTOOL_{G, S}RXFH
struct ethtool_rxnfc was originally defined in 2.6.27 for the
ETHTOOL_{G,S}RXFH command with only the cmd, flow_type and data
fields. It was then extended in 2.6.30 to support various additional
commands. These commands should have been defined to use a new
structure, but it is too late to change that now.
Since user-space may still be using the old structure definition
for the ETHTOOL_{G,S}RXFH commands, and since they do not need the
additional fields, only copy the originally defined fields to and
from user-space.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/ethtool.h | 2 ++
net/core/ethtool.c | 36 +++++++++++++++++++++++++++---------
2 files changed, 29 insertions(+), 9 deletions(-)
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 276b40a..b4207ca 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -379,6 +379,8 @@ struct ethtool_rxnfc {
__u32 flow_type;
/* The rx flow hash value or the rule DB size */
__u64 data;
+ /* The following fields are not valid and must not be used for
+ * the ETHTOOL_{G,X}RXFH commands. */
struct ethtool_rx_flow_spec fs;
__u32 rule_cnt;
__u32 rule_locs[0];
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index a3a7e9a..75e4ffe 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -318,23 +318,33 @@ out:
}
static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev,
- void __user *useraddr)
+ u32 cmd, void __user *useraddr)
{
- struct ethtool_rxnfc cmd;
+ struct ethtool_rxnfc info;
+ size_t info_size = sizeof(info);
if (!dev->ethtool_ops->set_rxnfc)
return -EOPNOTSUPP;
- if (copy_from_user(&cmd, useraddr, sizeof(cmd)))
+ /* struct ethtool_rxnfc was originally defined for
+ * ETHTOOL_{G,S}RXFH with only the cmd, flow_type and data
+ * members. User-space might still be using that
+ * definition. */
+ if (cmd == ETHTOOL_SRXFH)
+ info_size = (offsetof(struct ethtool_rxnfc, data) +
+ sizeof(info.data));
+
+ if (copy_from_user(&info, useraddr, info_size))
return -EFAULT;
- return dev->ethtool_ops->set_rxnfc(dev, &cmd);
+ return dev->ethtool_ops->set_rxnfc(dev, &info);
}
static noinline_for_stack int ethtool_get_rxnfc(struct net_device *dev,
- void __user *useraddr)
+ u32 cmd, void __user *useraddr)
{
struct ethtool_rxnfc info;
+ size_t info_size = sizeof(info);
const struct ethtool_ops *ops = dev->ethtool_ops;
int ret;
void *rule_buf = NULL;
@@ -342,7 +352,15 @@ static noinline_for_stack int ethtool_get_rxnfc(struct net_device *dev,
if (!ops->get_rxnfc)
return -EOPNOTSUPP;
- if (copy_from_user(&info, useraddr, sizeof(info)))
+ /* struct ethtool_rxnfc was originally defined for
+ * ETHTOOL_{G,S}RXFH with only the cmd, flow_type and data
+ * members. User-space might still be using that
+ * definition. */
+ if (cmd == ETHTOOL_GRXFH)
+ info_size = (offsetof(struct ethtool_rxnfc, data) +
+ sizeof(info.data));
+
+ if (copy_from_user(&info, useraddr, info_size))
return -EFAULT;
if (info.cmd == ETHTOOL_GRXCLSRLALL) {
@@ -360,7 +378,7 @@ static noinline_for_stack int ethtool_get_rxnfc(struct net_device *dev,
goto err_out;
ret = -EFAULT;
- if (copy_to_user(useraddr, &info, sizeof(info)))
+ if (copy_to_user(useraddr, &info, info_size))
goto err_out;
if (rule_buf) {
@@ -1517,12 +1535,12 @@ int dev_ethtool(struct net *net, struct ifreq *ifr)
case ETHTOOL_GRXCLSRLCNT:
case ETHTOOL_GRXCLSRULE:
case ETHTOOL_GRXCLSRLALL:
- rc = ethtool_get_rxnfc(dev, useraddr);
+ rc = ethtool_get_rxnfc(dev, ethcmd, useraddr);
break;
case ETHTOOL_SRXFH:
case ETHTOOL_SRXCLSRLDEL:
case ETHTOOL_SRXCLSRLINS:
- rc = ethtool_set_rxnfc(dev, useraddr);
+ rc = ethtool_set_rxnfc(dev, ethcmd, useraddr);
break;
case ETHTOOL_GGRO:
rc = ethtool_get_gro(dev, useraddr);
--
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