ethtool: Check that reserved fields of struct ethtool_rxfh are 0

We should fail rather than silently ignoring use of these extensions.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 8ae452a..17cb912 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -681,11 +681,11 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
 {
        int ret;
        const struct ethtool_ops *ops = dev->ethtool_ops;
-       u32 user_indir_size = 0, user_key_size = 0;
+       u32 user_indir_size, user_key_size;
        u32 dev_indir_size = 0, dev_key_size = 0;
+       struct ethtool_rxfh rxfh;
        u32 total_size;
-       u32 indir_offset, indir_bytes;
-       u32 key_offset;
+       u32 indir_bytes;
        u32 *indir = NULL;
        u8 *hkey = NULL;
        u8 *rss_config;
@@ -697,33 +697,24 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
 
        if (ops->get_rxfh_indir_size)
                dev_indir_size = ops->get_rxfh_indir_size(dev);
-
-       indir_offset = offsetof(struct ethtool_rxfh, indir_size);
-
-       if (copy_from_user(&user_indir_size,
-                          useraddr + indir_offset,
-                          sizeof(user_indir_size)))
-               return -EFAULT;
-
-       if (copy_to_user(useraddr + indir_offset,
-                        &dev_indir_size, sizeof(dev_indir_size)))
-               return -EFAULT;
-
        if (ops->get_rxfh_key_size)
                dev_key_size = ops->get_rxfh_key_size(dev);
 
        if ((dev_key_size + dev_indir_size) == 0)
                return -EOPNOTSUPP;
 
-       key_offset = offsetof(struct ethtool_rxfh, key_size);
-
-       if (copy_from_user(&user_key_size,
-                          useraddr + key_offset,
-                          sizeof(user_key_size)))
+       if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
                return -EFAULT;
+       user_indir_size = rxfh.indir_size;
+       user_key_size = rxfh.key_size;
 
-       if (copy_to_user(useraddr + key_offset,
-                        &dev_key_size, sizeof(dev_key_size)))
+       /* Check that reserved fields are 0 for now */
+       if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
+               return -EINVAL;
+
+       rxfh.indir_size = dev_indir_size;
+       rxfh.key_size = dev_key_size;
+       if (copy_to_user(useraddr, &rxfh, sizeof(rxfh)))
                return -EFAULT;
 
        /* If the user buffer size is 0, this is just a query for the
@@ -768,12 +759,11 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
        int ret;
        const struct ethtool_ops *ops = dev->ethtool_ops;
        struct ethtool_rxnfc rx_rings;
-       u32 user_indir_size = 0, dev_indir_size = 0, i;
-       u32 user_key_size = 0, dev_key_size = 0;
+       struct ethtool_rxfh rxfh;
+       u32 dev_indir_size = 0, dev_key_size = 0, i;
        u32 *indir = NULL, indir_bytes = 0;
        u8 *hkey = NULL;
        u8 *rss_config;
-       u32 indir_offset, key_offset;
        u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
 
        if (!(ops->get_rxfh_indir_size || ops->get_rxfh_key_size) ||
@@ -782,40 +772,33 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 
        if (ops->get_rxfh_indir_size)
                dev_indir_size = ops->get_rxfh_indir_size(dev);
-
-       indir_offset = offsetof(struct ethtool_rxfh, indir_size);
-       if (copy_from_user(&user_indir_size,
-                          useraddr + indir_offset,
-                          sizeof(user_indir_size)))
-               return -EFAULT;
-
        if (ops->get_rxfh_key_size)
                dev_key_size = dev->ethtool_ops->get_rxfh_key_size(dev);
-
        if ((dev_key_size + dev_indir_size) == 0)
                return -EOPNOTSUPP;
 
-       key_offset = offsetof(struct ethtool_rxfh, key_size);
-       if (copy_from_user(&user_key_size,
-                          useraddr + key_offset,
-                          sizeof(user_key_size)))
+       if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
                return -EFAULT;
 
+       /* Check that reserved fields are 0 for now */
+       if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
+               return -EINVAL;
+
        /* If either indir or hash key is valid, proceed further.
         * It is not valid to request that both be unchanged.
         */
-       if ((user_indir_size &&
-            user_indir_size != ETH_RXFH_INDIR_NO_CHANGE &&
-            user_indir_size != dev_indir_size) ||
-           (user_key_size && (user_key_size != dev_key_size)) ||
-           (user_indir_size == ETH_RXFH_INDIR_NO_CHANGE &&
-            user_key_size == 0))
+       if ((rxfh.indir_size &&
+            rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE &&
+            rxfh.indir_size != dev_indir_size) ||
+           (rxfh.key_size && (rxfh.key_size != dev_key_size)) ||
+           (rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE &&
+            rxfh.key_size == 0))
                return -EINVAL;
 
-       if (user_indir_size != ETH_RXFH_INDIR_NO_CHANGE)
+       if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
                indir_bytes = dev_indir_size * sizeof(indir[0]);
 
-       rss_config = kzalloc(indir_bytes + user_key_size, GFP_USER);
+       rss_config = kzalloc(indir_bytes + rxfh.key_size, GFP_USER);
        if (!rss_config)
                return -ENOMEM;
 
@@ -824,29 +807,29 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
        if (ret)
                goto out;
 
-       /* user_indir_size == 0 means reset the indir table to default.
-        * user_indir_size == ETH_RXFH_INDIR_NO_CHANGE means leave it unchanged.
+       /* rxfh.indir_size == 0 means reset the indir table to default.
+        * rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE means leave it unchanged.
         */
-       if (user_indir_size &&
-           user_indir_size != ETH_RXFH_INDIR_NO_CHANGE) {
+       if (rxfh.indir_size &&
+           rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE) {
                indir = (u32 *)rss_config;
                ret = ethtool_copy_validate_indir(indir,
                                                  useraddr + rss_cfg_offset,
                                                  &rx_rings,
-                                                 user_indir_size);
+                                                 rxfh.indir_size);
                if (ret)
                        goto out;
-       } else if (user_indir_size == 0) {
+       } else if (rxfh.indir_size == 0) {
                indir = (u32 *)rss_config;
                for (i = 0; i < dev_indir_size; i++)
                        indir[i] = ethtool_rxfh_indir_default(i, rx_rings.data);
        }
 
-       if (user_key_size) {
+       if (rxfh.key_size) {
                hkey = rss_config + indir_bytes;
                if (copy_from_user(hkey,
                                   useraddr + rss_cfg_offset + indir_bytes,
-                                  user_key_size)) {
+                                  rxfh.key_size)) {
                        ret = -EFAULT;
                        goto out;
                }