[09/63] ethtool: Compat handling for struct ethtool_rxnfc

From: Greg KH
Date: Fri Mar 25 2011 - 20:27:31 EST


2.6.38-stable review patch. If anyone has any objections, please let us know.

------------------

From: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>

commit 3a7da39d165e0c363c294feec119db1427032afd upstream.

This structure was accidentally defined such that its layout can
differ between 32-bit and 64-bit processes. Add compat structure
definitions and an ioctl wrapper function.

Signed-off-by: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
Acked-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
include/linux/ethtool.h | 34 ++++++++++++++
net/socket.c | 114 +++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 141 insertions(+), 7 deletions(-)

--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -13,6 +13,9 @@
#ifndef _LINUX_ETHTOOL_H
#define _LINUX_ETHTOOL_H

+#ifdef __KERNEL__
+#include <linux/compat.h>
+#endif
#include <linux/types.h>
#include <linux/if_ether.h>

@@ -449,6 +452,37 @@ struct ethtool_rxnfc {
__u32 rule_locs[0];
};

+#ifdef __KERNEL__
+#ifdef CONFIG_COMPAT
+
+struct compat_ethtool_rx_flow_spec {
+ u32 flow_type;
+ union {
+ struct ethtool_tcpip4_spec tcp_ip4_spec;
+ struct ethtool_tcpip4_spec udp_ip4_spec;
+ struct ethtool_tcpip4_spec sctp_ip4_spec;
+ struct ethtool_ah_espip4_spec ah_ip4_spec;
+ struct ethtool_ah_espip4_spec esp_ip4_spec;
+ struct ethtool_usrip4_spec usr_ip4_spec;
+ struct ethhdr ether_spec;
+ u8 hdata[72];
+ } h_u, m_u;
+ compat_u64 ring_cookie;
+ u32 location;
+};
+
+struct compat_ethtool_rxnfc {
+ u32 cmd;
+ u32 flow_type;
+ compat_u64 data;
+ struct compat_ethtool_rx_flow_spec fs;
+ u32 rule_cnt;
+ u32 rule_locs[0];
+};
+
+#endif /* CONFIG_COMPAT */
+#endif /* __KERNEL__ */
+
/**
* struct ethtool_rxfh_indir - command to get or set RX flow hash indirection
* @cmd: Specific command number - %ETHTOOL_GRXFHINDIR or %ETHTOOL_SRXFHINDIR
--- a/net/socket.c
+++ b/net/socket.c
@@ -2583,23 +2583,123 @@ static int dev_ifconf(struct net *net, s

static int ethtool_ioctl(struct net *net, struct compat_ifreq __user *ifr32)
{
+ struct compat_ethtool_rxnfc __user *compat_rxnfc;
+ bool convert_in = false, convert_out = false;
+ size_t buf_size = ALIGN(sizeof(struct ifreq), 8);
+ struct ethtool_rxnfc __user *rxnfc;
struct ifreq __user *ifr;
+ u32 rule_cnt = 0, actual_rule_cnt;
+ u32 ethcmd;
u32 data;
- void __user *datap;
+ int ret;

- ifr = compat_alloc_user_space(sizeof(*ifr));
+ if (get_user(data, &ifr32->ifr_ifru.ifru_data))
+ return -EFAULT;

- if (copy_in_user(&ifr->ifr_name, &ifr32->ifr_name, IFNAMSIZ))
+ compat_rxnfc = compat_ptr(data);
+
+ if (get_user(ethcmd, &compat_rxnfc->cmd))
return -EFAULT;

- if (get_user(data, &ifr32->ifr_ifru.ifru_data))
+ /* Most ethtool structures are defined without padding.
+ * Unfortunately struct ethtool_rxnfc is an exception.
+ */
+ switch (ethcmd) {
+ default:
+ break;
+ case ETHTOOL_GRXCLSRLALL:
+ /* Buffer size is variable */
+ if (get_user(rule_cnt, &compat_rxnfc->rule_cnt))
+ return -EFAULT;
+ if (rule_cnt > KMALLOC_MAX_SIZE / sizeof(u32))
+ return -ENOMEM;
+ buf_size += rule_cnt * sizeof(u32);
+ /* fall through */
+ case ETHTOOL_GRXRINGS:
+ case ETHTOOL_GRXCLSRLCNT:
+ case ETHTOOL_GRXCLSRULE:
+ convert_out = true;
+ /* fall through */
+ case ETHTOOL_SRXCLSRLDEL:
+ case ETHTOOL_SRXCLSRLINS:
+ buf_size += sizeof(struct ethtool_rxnfc);
+ convert_in = true;
+ break;
+ }
+
+ ifr = compat_alloc_user_space(buf_size);
+ rxnfc = (void *)ifr + ALIGN(sizeof(struct ifreq), 8);
+
+ if (copy_in_user(&ifr->ifr_name, &ifr32->ifr_name, IFNAMSIZ))
return -EFAULT;

- datap = compat_ptr(data);
- if (put_user(datap, &ifr->ifr_ifru.ifru_data))
+ if (put_user(convert_in ? rxnfc : compat_ptr(data),
+ &ifr->ifr_ifru.ifru_data))
return -EFAULT;

- return dev_ioctl(net, SIOCETHTOOL, ifr);
+ if (convert_in) {
+ /* We expect there to be holes between fs.m_u and
+ * fs.ring_cookie and at the end of fs, but nowhere else.
+ */
+ BUILD_BUG_ON(offsetof(struct compat_ethtool_rxnfc, fs.m_u) +
+ sizeof(compat_rxnfc->fs.m_u) !=
+ offsetof(struct ethtool_rxnfc, fs.m_u) +
+ sizeof(rxnfc->fs.m_u));
+ BUILD_BUG_ON(
+ offsetof(struct compat_ethtool_rxnfc, fs.location) -
+ offsetof(struct compat_ethtool_rxnfc, fs.ring_cookie) !=
+ offsetof(struct ethtool_rxnfc, fs.location) -
+ offsetof(struct ethtool_rxnfc, fs.ring_cookie));
+
+ if (copy_in_user(rxnfc, compat_rxnfc,
+ (void *)(&rxnfc->fs.m_u + 1) -
+ (void *)rxnfc) ||
+ copy_in_user(&rxnfc->fs.ring_cookie,
+ &compat_rxnfc->fs.ring_cookie,
+ (void *)(&rxnfc->fs.location + 1) -
+ (void *)&rxnfc->fs.ring_cookie) ||
+ copy_in_user(&rxnfc->rule_cnt, &compat_rxnfc->rule_cnt,
+ sizeof(rxnfc->rule_cnt)))
+ return -EFAULT;
+ }
+
+ ret = dev_ioctl(net, SIOCETHTOOL, ifr);
+ if (ret)
+ return ret;
+
+ if (convert_out) {
+ if (copy_in_user(compat_rxnfc, rxnfc,
+ (const void *)(&rxnfc->fs.m_u + 1) -
+ (const void *)rxnfc) ||
+ copy_in_user(&compat_rxnfc->fs.ring_cookie,
+ &rxnfc->fs.ring_cookie,
+ (const void *)(&rxnfc->fs.location + 1) -
+ (const void *)&rxnfc->fs.ring_cookie) ||
+ copy_in_user(&compat_rxnfc->rule_cnt, &rxnfc->rule_cnt,
+ sizeof(rxnfc->rule_cnt)))
+ return -EFAULT;
+
+ if (ethcmd == ETHTOOL_GRXCLSRLALL) {
+ /* As an optimisation, we only copy the actual
+ * number of rules that the underlying
+ * function returned. Since Mallory might
+ * change the rule count in user memory, we
+ * check that it is less than the rule count
+ * originally given (as the user buffer size),
+ * which has been range-checked.
+ */
+ if (get_user(actual_rule_cnt, &rxnfc->rule_cnt))
+ return -EFAULT;
+ if (actual_rule_cnt < rule_cnt)
+ rule_cnt = actual_rule_cnt;
+ if (copy_in_user(&compat_rxnfc->rule_locs[0],
+ &rxnfc->rule_locs[0],
+ rule_cnt * sizeof(u32)))
+ return -EFAULT;
+ }
+ }
+
+ return 0;
}

static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)


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