[PATCH v3] graph: avoid id collisions

[David Marchand]

On Tue, Jun 18, 2024 at 11:24 AM Robin Jarry <rjarry at redhat.com> wrote:
>
> The graph id is determined based on a global variable that is
> incremented every time a graph is created, and decremented every time
> a graph is destroyed. This only works if graphs are destroyed in the
> reverse order in which they have been created.
>
> The following code produces duplicate graph IDs which can lead to
> use-after-free bugs and other undefined behaviours:
>
>   a = rte_graph_create(...); // id=0 graph_id=1
>   b = rte_graph_create(...); // id=1 graph_id=2
>   rte_graph_destroy(a);      // graph_id=1
>   c = rte_graph_create(...); // id=1 graph_id=2 (duplicate with b)
>   rte_graph_destroy(c);      // frees memory still used by b
>
> Remove the global counter. Make sure that the graph list is always
> ordered by increasing graph ids. When creating a new graph, pick a free
> id which is not allocated.
>
> Update unit tests to ensure it works as expected.

Fixes: a91fecc19c5c ("graph: implement create and destroy")
Cc: stable at dpdk.org

>
> Signed-off-by: Robin Jarry <rjarry at redhat.com>

Acked-by: Kiran Kumar Kokkilagadda <kirankumark at marvell.com>

Applied, thanks.


-- 
David Marchand