net_shaper_nl_group_doit() does not deduplicate NET_SHAPER_A_LEAVES
entries. When userspace supplies the same leaf handle twice, the same
old-parent pointer lands twice in old_nodes[]. The cleanup loop double
frees the parent. Of course the same parent may still be in old_nodes[]
twice if we are moving multiple of its leaves.
Note that this patch also implicitly fixes the fact that the
i >= leaves_count path forgets to set ret.
Fixes: 5d5d4700e75d ("net-shapers: implement NL group operation")
Signed-off-by: Jakub Kicinski <[email protected]>
---
net/shaper/shaper.c | 60 +++++++++++++++++++++++++++++++++------------
1 file changed, 45 insertions(+), 15 deletions(-)
diff --git a/net/shaper/shaper.c b/net/shaper/shaper.c
index a2e9adca9afc..a27673e5919f 100644
--- a/net/shaper/shaper.c
+++ b/net/shaper/shaper.c
@@ -955,6 +955,46 @@ static int net_shaper_handle_cmp(const struct
net_shaper_handle *a,
return memcmp(a, b, sizeof(*a));
}
+static int net_shaper_parse_leaves(struct net_shaper_binding *binding,
+ struct genl_info *info,
+ const struct net_shaper *node,
+ struct net_shaper *leaves,
+ int leaves_count)
+{
+ struct nlattr *attr;
+ int i, j, ret, rem;
+
+ i = 0;
+ nla_for_each_attr_type(attr, NET_SHAPER_A_LEAVES,
+ genlmsg_data(info->genlhdr),
+ genlmsg_len(info->genlhdr), rem) {
+ if (WARN_ON_ONCE(i >= leaves_count))
+ return -EINVAL;
+
+ ret = net_shaper_parse_leaf(binding, attr, info,
+ node, &leaves[i]);
+ if (ret)
+ return ret;
+
+ /* Reject duplicates */
+ for (j = 0; j < i; j++) {
+ if (net_shaper_handle_cmp(&leaves[i].handle,
+ &leaves[j].handle))
+ continue;
+
+ NL_SET_ERR_MSG_ATTR_FMT(info->extack, attr,
+ "Duplicate leaf shaper %d:%d",
+ leaves[i].handle.scope,
+ leaves[i].handle.id);
+ return -EINVAL;
+ }
+
+ i++;
+ }
+
+ return 0;
+}
+
static int net_shaper_parent_from_leaves(int leaves_count,
const struct net_shaper *leaves,
struct net_shaper *node,
@@ -1195,10 +1235,9 @@ int net_shaper_nl_group_doit(struct sk_buff *skb, struct
genl_info *info)
struct net_shaper **old_nodes, *leaves, node = {};
struct net_shaper_hierarchy *hierarchy;
struct net_shaper_binding *binding;
- int i, ret, rem, leaves_count;
+ int i, ret, leaves_count;
int old_nodes_count = 0;
struct sk_buff *msg;
- struct nlattr *attr;
if (GENL_REQ_ATTR_CHECK(info, NET_SHAPER_A_LEAVES))
return -EINVAL;
@@ -1226,19 +1265,10 @@ int net_shaper_nl_group_doit(struct sk_buff *skb,
struct genl_info *info)
if (ret)
goto free_leaves;
- i = 0;
- nla_for_each_attr_type(attr, NET_SHAPER_A_LEAVES,
- genlmsg_data(info->genlhdr),
- genlmsg_len(info->genlhdr), rem) {
- if (WARN_ON_ONCE(i >= leaves_count))
- goto free_leaves;
-
- ret = net_shaper_parse_leaf(binding, attr, info,
- &node, &leaves[i]);
- if (ret)
- goto free_leaves;
- i++;
- }
+ ret = net_shaper_parse_leaves(binding, info, &node,
+ leaves, leaves_count);
+ if (ret)
+ goto free_leaves;
/* Prepare the msg reply in advance, to avoid device operation
* rollback on allocation failure.
--
2.54.0
