After creating at least one graph and calling rte_node_edge_update to
add a new edge on a node which is in use in the graph, the node memory
is reallocated but the active graph still has a pointer to the freed
memory.
When destroying the graph, it causes a use-after-free error detected by
libasan:
ERROR: AddressSanitizer: heap-use-after-free
READ of size 8 at 0x7c4baa5e4da8 thread T0
#0 0x0000005ad224 in graph_node_fini lib/graph/graph.c:256
#1 0x0000005ae657 in rte_graph_destroy lib/graph/graph.c:504
...
freed by thread T0 here:
#0 0x7f1bac4e5e4b in realloc.part.0 (/lib64/libasan.so.8+0xe5e4b)
#1 0x0000005ab6d7 in edge_update lib/graph/node.c:271
#2 0x0000005abb1b in rte_node_edge_update lib/graph/node.c:339
...
previously allocated by thread T0 here:
#0 0x7f1bac4e5e4b in realloc.part.0 (/lib64/libasan.so.8+0xe5e4b)
#1 0x0000005ab6d7 in edge_update lib/graph/node.c:271
#2 0x0000005abb1b in rte_node_edge_update lib/graph/node.c:339
...
Use malloc+memcpy and add an internal function to replace all references
to the old node memory before freeing it.
Cc: [email protected]
Fixes: c59dac2ca14a ("graph: implement node operations")
Signed-off-by: Robin Jarry <[email protected]>
---
lib/graph/graph.c | 14 ++++++++++++++
lib/graph/graph_private.h | 12 ++++++++++++
lib/graph/node.c | 6 +++++-
3 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/lib/graph/graph.c b/lib/graph/graph.c
index 61159edc7261..6911ea8abeed 100644
--- a/lib/graph/graph.c
+++ b/lib/graph/graph.c
@@ -277,6 +277,20 @@ graph_node_fini(struct graph *graph)
graph_node->node->name));
}
+void
+graph_node_replace_all(struct node *old, struct node *new)
+{
+ struct graph_node *graph_node;
+ struct graph *graph;
+
+ STAILQ_FOREACH(graph, &graph_list, next) {
+ STAILQ_FOREACH(graph_node, &graph->node_list, next) {
+ if (graph_node->node == old)
+ graph_node->node = new;
+ }
+ }
+}
+
static struct rte_graph *
graph_mem_fixup_node_ctx(struct rte_graph *graph)
{
diff --git a/lib/graph/graph_private.h b/lib/graph/graph_private.h
index 21912c0ae63f..26cdc6637192 100644
--- a/lib/graph/graph_private.h
+++ b/lib/graph/graph_private.h
@@ -299,6 +299,18 @@ int graph_node_has_edge_to_src_node(struct graph *graph);
*/
int graph_node_has_loop_edge(struct graph *graph);
+/**
+ * @internal
+ *
+ * Replace all pointers of a given node with another one in all active graphs.
+ *
+ * @param old
+ * Node pointer to replace in all graphs.
+ * @param new
+ * Updated pointer.
+ */
+void graph_node_replace_all(struct node *old, struct node *new);
+
/**
* @internal
*
diff --git a/lib/graph/node.c b/lib/graph/node.c
index cae1c809edc4..e3359fe490a5 100644
--- a/lib/graph/node.c
+++ b/lib/graph/node.c
@@ -325,11 +325,15 @@ edge_update(struct node *node, struct node *prev,
rte_edge_t from,
need_realloc = max_edges > node->nb_edges;
if (need_realloc) {
sz = sizeof(struct node) + (max_edges * RTE_NODE_NAMESIZE);
- new_node = realloc(node, sz);
+ new_node = malloc(sz);
if (new_node == NULL) {
rte_errno = ENOMEM;
goto restore;
} else {
+ sz = sizeof(*node) + (node->nb_edges *
RTE_NODE_NAMESIZE);
+ memcpy(new_node, node, sz);
+ graph_node_replace_all(node, new_node);
+ free(node);
node = new_node;
}
}
--
2.51.1
