ethtool: Compat handling for struct ethtool_rxnfc
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@solarflare.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: stable@kernel.org [2.6.30+]
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index 937d0fc..5212447 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2588,23 +2588,123 @@
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;
-
- ifr = compat_alloc_user_space(sizeof(*ifr));
-
- if (copy_in_user(&ifr->ifr_name, &ifr32->ifr_name, IFNAMSIZ))
- return -EFAULT;
+ int ret;
if (get_user(data, &ifr32->ifr_ifru.ifru_data))
return -EFAULT;
- datap = compat_ptr(data);
- if (put_user(datap, &ifr->ifr_ifru.ifru_data))
+ compat_rxnfc = compat_ptr(data);
+
+ if (get_user(ethcmd, &compat_rxnfc->cmd))
return -EFAULT;
- return dev_ioctl(net, SIOCETHTOOL, ifr);
+ /* 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;
+
+ if (put_user(convert_in ? rxnfc : compat_ptr(data),
+ &ifr->ifr_ifru.ifru_data))
+ return -EFAULT;
+
+ 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)