+ 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;